Internet Notes by Systems)

8/14/2019 Internet Notes by Systems)

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Presented by: Tejas. B. Prajapati (MMS-II)-Systems

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CREATION / HISTORY OF THE INTERNET

The word Internet has been coined from the words, Interconnections andNetworks. The Internet was born in 1969, out of efforts to connect together a US

Defence Department network called the ARPAnet (Advanced Research Projects Agency

Network) and various other radio and satellite networks. In order to share information,researchers and scientists from universities and research laboratories developed theinterconnection of their computers and over time, the internet has become a global

resource. The internet has grown explosively in the 1990s. It is composed of over 30,000connected networks from more than 100 countries. Today the internet as become ainformation superhighway consisting of billions of people connected to each other.

As of January 11, 2007, 1.093 billion people use the Internet according to Internet WorldStats.

BASICS OF THE INTERNET

The Internet is the worldwide, publicly accessible,network of interconnectedcomputer networks that transmit data by packet switching using the standard Internet

Protocol (IP).

It is a "network of networks" that consists of millions of smaller domestic, academic,business, and government networks, which together carry various information and

services, such as electronic mail, online chat, file transfer, and the interlinked Webpages and other documents of the World Wide Web.

TERMINOLOGY: INTERNET VS. WEB

The Internet and the World Wide Web are not synonymous.

The Internet is a collection of interconnected computer networks, linked by copper

wires, fiber-optic cables, wireless connections, etc.

The Web is a collection of interconnected documents and other resources, linked byhyperlinks and URLs.

Many people believe that the Web and the Internet are

the same thing, but this is not correct. In fact, they aretwo different things. The Web is a service (a system for

accessing documents) that is supported by the Internet (agigantic network). The World Wide Web is accessible via

the Internet, as are many other services including e-mail,file sharing etc.


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INTERNET STRUCTURE

There have been many analyses of the Internet and its structure. In network schematic

diagrams, the Internet is often represented by a cloud symbol, into and out of whichnetwork communications can pass.

INTERNET PROTOCOLS

Protocols are the rules that govern data and its communication. They allowcooperating computers to share or understand each other across a network.

There are three layers of protocols:

At the lowest level is IP (Internet Protocol), which defines the data-grams or

packets that carry blocks of data from one node to another.The vast majority of today's Internet uses version four of the IP protocol(i.e. IPv4), and although IPv6 is standardized, it exists only as "islands" of

connectivity, and there are many ISPs who don't have any IPv6 connectivity at all.

Next come TCP (Transmission Control Protocol) and UDP (User DatagramProtocol) - the protocols by which one host sends data to another.

The former makes a virtual 'connection', which gives some level of

guarantee of reliability. The latter is a best-effort, connectionless transport, inwhich data packets that are lost in transit will not be re-sent.

On top comes the Application protocol. This defines the specific messages anddata formats sent and understood by the applications running at each end of thecommunication. Ex: HTTP (Hypertext transfer protocol), FTP(File TransferProtocol), SMTP(Simple Mail Transfer Protocol).


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ICANN

The Internet Corporation for Assigned Names and Numbers (ICANN) is theauthority that coordinates the assignment of unique identifiers on the Internet, including

domain names, Internet protocol addresses, and protocol port. A globally unified

namespace (i.e., a system of names in which there is one and only one holder of eachname) is essential for the Internet to function.Because the Internet is a distributed network comprising many voluntarily interconnected

networks, the Internet, as such, has no governing body. ICANN's role in coordinating theassignment of unique identifiers distinguishes it as perhaps the only central coordinating

body on the global Internet.

LANGUAGE

The most prevalent language for communication on the Internet is English. TheInternet's technologies have developed enough in recent years that good facilities are

available for development and communication in most widely used languages likeDeutsch, Hindi, Italiano, Marathi to name a few.

HOW THE WEB WORKS

Web documents can be linked together because they are created in a format known as

hypertext. Hypertext systems provide an easy way to manage large collections of data,

which can include text files, pictures, sounds, movies, and more.

To support hypertext documents, the Web uses a special protocol, called the hypertexttransfer protocol, or HTTP. A hypertext document is a specially encoded file that uses

the hypertext markup language, or HTML. This language allows a documents author toembed hypertext linksalso called hyperlinks or just linksin the document.

HTTP and hypertext links are the foundations of the World Wide Web. As you read

a hypertext documentmore commonly called a Web pageon screen, you can click aword or a picture encoded as a hypertext link and immediately jumps to another location

within the same document or to a different Web page. The second page may be locatedon the same computer as the original page, or anywhere else on the Internet.

A collection of related Web pages is called a Web site. Web sites are housed on Webservers, Internet host computers that often store thousands of individual pages. Copying a

page onto a server is called publishing the page, but the process also is called posting oruploading. Web pages are used to distribute news, interactive educational services,

product information, catalogs, highway traffic reports, and live audio and video, amongmany others.


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How to access the Internet

The Internet is a gigantic collection of millions of computers, all linked together on a

computer network. The network allows all of the computers to communicate with oneanother. A home computer may be linked to the Internet using a phone-line modem, DSL

or cable modem that talks to an Internet service provider (ISP). A computer in a businessor university will usually have a network interface card (NIC) that directly connects it to

a local area network(LAN) inside the business. The business can then connect its LANto an ISP using a high-speed phone line like a T1 line. A T1 line can handle

approximately 1.5 million bits per second, while a normal phone line using a modem cantypically handle 30,000 to 50,000 bits per second.

ISPs then connect to larger ISPs, and the largest ISPs maintain fiber-optic "backbones"

for an entire nation or region. Backbones around the world are connected through fiber-

optic lines, undersea cables or satellite links (see An Atlas of Cyberspaces for someinteresting backbone maps). In this way, every computer on the Internet is connected toevery other computer on the Internet.

Common methods of home access include dial-up, landline broadband (over coaxialcable, fibre optic or copper wires), Wi-Fi,satellite and cell phones.

Public places to use the Internet include libraries and Internet cafes, where computerswith Internet connections are available. There are also Internet access points in many


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public places such as airport halls and coffee shops, in some cases just for brief use whilestanding.

Wi-Fi provides wireless access to computer networks, and therefore can do so to the

Internet itself. Hotspots providing such access include Wi-Fi-cafes, where a would-be

user needs to bring their own wireless-enabled devices such as a laptop or PDA. Theseservices may be free to all, free to customers only, or fee-based. A hotspot need not belimited to a confined location. The whole campus or park, or even the entire city can be

enabled.

High-end mobile phones such as smartphones generally come with Internet accessthrough the phone network. Web browsers such as Opera are available on these advanced

handsets, which can also run a wide variety of other Internet software.

Clients and Servers

In general, all of the machines on the Internet can be categorized as two types: servers

and clients. Those machines that provide services (like Web servers or FTP servers) toother machines are servers. And the machines that are used to connect to those servicesare clients. When you connect to Yahoo! at www.yahoo.com to read a page, Yahoo! is

providing a machine (probably a cluster of very large machines), for use on the Internet,to service your request. Yahoo! is providing a server. Your machine, on the other hand, is

probably providing no services to anyone else on the Internet. Therefore, it is a usermachine, also known as a client.

A server machine may provide one or more services on the Internet. For example, a

server machine might have software running on it that allows it to act as a Web server, ane-mail server and an FTP server. Clients direct their requests to a specific software server

running on the overall server machine. For example, if you are running a Web browser onyour machine, it will most likely want to talk to the Web server on the server machine.

Your Telnet application will want to talk to the Telnet server, your e-mail application willtalk to the e-mail server, and so on...

IP Addresses

To keep all of these machines straight, each machine on the Internet is assigned a unique

address called an IP address. IP stands for Internet protocol, and these addresses are32-bit numbers, normally expressed as four "octets" in a "dotted decimal number." A

typical IP address looks like this:216.27.61.137

The four numbers in an IP address are called octets because they can have values

between 0 and 255, which is 28 possibilities per octet.

Every machine on the Internet has a unique IP address. A server has a static IP address

that does not change very often. A home machine that is dialing up through a modemoften has an IP address that is assigned by the ISP when the machine dials in. That IP


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address is unique for that session -- it may be different the next time the machine dials in.This way, an ISP only needs one IP address for each modem it supports, rather than for

each customer.

WEB BROWSERS

For several years, the Web remained an interesting but not particularly exciting tool usedby scientific researchers. But in 1993, developers at the National Center for

Supercomputing Applications (NCSA) created Mosaic, a point-and-click Web browser.

A Web browser (or browser) is a software application designed to find hypertext

documents on the Web and then open the documents on the users computer. Apoint-and-click browser provides a graphical user interface that enables the user to click

hyperlinked text and images to jump to other documents or view other data. Several text-based Web browsers are also available and are used in non-graphical operating systems,

such as certain versions of UNIX. Mosaic and Web browsers that evolved from it havechanged the way people use the Internet. Today, the most popular graphical Web

browsers are Microsofts Internet Explorer and Mozilla Firefox.

URLs

The hypertext transfer protocol uses Internet addresses in a special format, called a

Uniform Resource Locator, or URL. URLs look like this:

type://address/path

In a URL, type specifies the type of server in which the file is located, address is the

address of the server, and path is the location within the file structure of the server. The

path includes the list of folders where the desired file (the Web page itself or some otherpiece of data) is located.

Consider the URL for a page at the Library of Congress Web site, which containsinformation about the Librarys collection of permanent.


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WHAT IS A WEB SERVER

Have you ever wondered about the mechanisms that delivered this page to you?

when you clicked on the link for this page, or typed in its URL (uniform resourcelocator), what happened behind the scenes to bring this page onto your screen?

Let's say that you are sitting at your computer, surfing the Web, and you get a call from a

friend who says, "I just read a great article! Type in this URL and check it out. It's athttp://www.howstuffworks.com/web-server.htm." So you type that URL into your

browser and press return. And magically, no matter where in the world that URL lives,the page pops up on your screen.

At the most basic level possible, the following diagram shows the steps that brought that

page to your screen:

Your browser formed a connection to a Web server, requested a page and received it.


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Behind the Scenes

* The browser broke the URL into three parts:1. The protocol ("http")

2. The server name ("www.howstuffworks.com")3. The file name ("web-server.htm")

* The browser communicated with a name server to translate the server name

"www.howstuffworks.com" into an IP Address, which it uses to connect to the servermachine.

* The browser then formed a connection to the server at that IP address on port 80.

* Following the HTTP protocol, the browser sent a GET request to the server, asking

for the file "http://www.howstuffworks.com/web-server.htm." (Note that cookies may besent from browser to server with the GET request -- see How Internet Cookies Work for

details.)

* The server then sent the HTML text for the Web page to the browser. (Cookies mayalso be sent from server to browser in the header for the page.)

* The browser read the HTML tags and formatted the page onto your screen.

WHAT IS A DNS SERVER

Domain Names

Because most people have trouble remembering the strings of numbers that make up IPaddresses, and because IP addresses sometimes need to change, all servers on the Internet

also have human-readable names, called domain names. For example,www.howstuffworks.com is a permanent, human-readable name. It is easier for most of

us to remember www.howstuffworks.com than it is to remember 209.116.69.66.

The name www.howstuffworks.com actually has three parts:

1. The host name ("www")2. The domain name ("howstuffworks")3. The top-level domain name ("com")

Domain names within the ".com" domain are managed by the registrar called VeriSign.

VeriSign also manages ".net" domain names. VeriSign creates the top-level domainnames and guarantees that all names within a top-level domain are unique.

The host name is created by the company hosting the domain. "www" is a very common

host name, but many places now either omit it or replace it with a different host name thatindicates a specific area of the site. For example, in encarta.msn.com, the domain name

for Microsoft's Encarta encyclopedia, "encarta" is designated as the host name instead of"www."


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Name Servers

A set of servers called domain name servers (DNS) maps

the human-readable names to the IP addresses. These

servers are simple databases that map names to IPaddresses, and they are distributed all over the Internet.

If you type the URL

"http://www.howstuffworks.com/web-server.htm" into

your browser, your browser extracts the name"www.howstuffworks.com," passes it to a domain name

server, and the domain name server returns the correct IPaddress for www.howstuffworks.com. A number of name servers may be involved to get

the right IP address.

Ports

Any server machine makes its services available to the Internet using numbered ports,one for each service that is available on the server. For example, if a server machine isrunning a Web server and an FTP server, the Web server would typically be available on

port 80, and the FTP server would be available on port 21.

Note that there is nothing that forces, for example, a Web server to be on port 80. If youwere to set up your own machine and load Web server software on it, you could put the

Web server on port 918, or any other unused port, if you wanted to. Then, if yourmachine were known as xxx.yyy.com, someone on the Internet could connect to your

server with the URL http://xxx.yyy.com:918. The ":918" explicitly specifies the portnumber, and would have to be included for someone to reach your server. When no port

is specified, the browser simply assumes that the server is using the well-known port 80.

A Resolver looks up the information associated with nodes. A resolver knows how tocommunicate with name servers by sending DNS requests, and heeding DNS responses.

Resolving usually entails iterating through several name servers to find the neededinformation.

Some resolvers function simplistically and can only communicate with a single nameserver. These simple resolvers rely on a recursing name server to perform the work of

finding information for them.

The whois CommandOn a UNIX machine, you can

use the whois command to lookup information about a domainname. You can do the samething using the whois form atVeriSign. If you type in a domainname, like "howstuffworks.com,"it will return to you theregistration information for thatdomain, including its IP address.


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WHAT IS FTP

The FTP (File Transfer Protocol) utility program is commonly used for copying files toand from other computers. Most operating systems and communication programs now

include some form of an FTP utility program, but the commands differ slightly betweenthem. You can also perform FTP through a browser. For example, bring up Internet

Explorer and type inftp://yourLoginName@IPaddress

If the remote machine has been reached successfully, FTP responds by asking for aloginname andpassword.

When you enter your own loginname andpasswordfor the remote machine, it returns theprompt

ftp>

and permits you access to your own home directory on the remote machine. You should

be able to move around in your own directory and to copy files to and from your localmachine using the FTP interface commands

? to requesthelp or information about the FTP commands

bye to exit the FTP environment (same as quit)

cd to change directory on the remote machine

close to terminate a connection with another computer

delete to delete (remove) a file in the current remote directory

get to copy one file from the remote machine to the local machine

put to copy one file from the local machine to the remote machine

An example of a normal ftp operation with file uploading

% ftp nordsieck.cs.colorado.eduConnected to nordsieck.cs.colorado.edu.

220 nordsieck FTP server (Version 5.53 Tue Aug 25 10:46:12 MDT 1992)

ready.

Name (nordsieck.cs.colorado.edu:yourlogin): yourlogin

331 Password required for yourlogin.

Password:

230 User yourlogin logged in.

ftp>

ftp>put tmul.out

200 PORT command successful.

150 Opening ASCII mode data connection for tmul.out.

226 Transfer complete.

ftp>bye

221 Goodbye.


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COMMON USES / APPLICATION OF THE INTERNET

E-MAIL: The concept of sending electronic text messages betweenparties in a way analogous to mailing letters or memos predates thecreation of the Internet.

Every day, the citizens of the Internet send each other billions of e-mailmessages. e-mail has become an extremely popular communication tool.

Have you ever wondered how e-mail gets from your desktop to a friend halfway

around the world?

An e-mail message has always been nothing more than a simple text message -- apiece of text sent to a recipient. In the beginning and even today, e-mail messages tend to

be short pieces of text, although the ability to add attachments now makes many e-mailmessages quite long. Even with attachments, however, e-mail messages continue to be

text messages.

E-mail ClientsYou have probably already received several e-mail messages today. To look at them, you

use some sort of e-mail client. Many people use well-known stand-alone clients likeMicrosoft Outlook, Outlook Express, Eudora or Pegasus. People who subscribe to free e-

mail services like Hotmail or Yahoo use an e-mail client that appears in a Web page.

No matter which type of client you are using, it generally does four things:

It shows you a list of all of the messages in your mailbox by displaying the

message headers. The header shows you who sent the mail, the subject of the

mail and may also show the time and date of the message and the message size. It lets you select a message header and read the body of the e-mail message. It lets you create new messages and send them. You type in the e-mail address of

the recipient and the subject for the message, and then type the body of themessage.

Most e-mail clients also let you add attachments to messages you send and savethe attachments from messages you receive.

A Simple E-mail ServerGiven that you have an e-mail client on your machine, you are ready to send and receive

e-mail. All that you need is an e-mail server for the client to connect to.

The simplest possible e-mail server would work something like this:

It would have a list of e-mail accounts, with one account for each person who canreceive e-mail on the server. My account name might be mbrain, John Smith's

might bejsmith, and so on.


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It would have a text file for each account in the list. So the server would have atext file in its directory named MBRAIN.TXT, another named JSMITH.TXT, and

so on.

If someone wanted to send me a message, the person would compose a text

message ("Marshall, Can we have lunch Monday? John") in an e-mail client, and

indicate that the message should go to mbrain. When the person presses the Sendbutton, the e-mail client would connect to the e-mail server and pass to the serverthe name of the recipient (mbrain), the name of the sender (jsmith) and the body

of the message.

The server would format those pieces of information and append them to the

bottom of the MBRAIN.TXT file. The entry in the file might look like this: From: jsmith

To: mbrain

Marshall,

Can we have lunch Monday?

John

There are several other pieces of information that the server might save into the file, likethe time and date of receipt and a subject line; but overall, you can see that this is an

extremely simple process.

As other people sent mail to mbrain, the server would simply append those messages tothe bottom of the file in the order that they arrived. The text file would accumulate a

series of five or 10 messages, and eventually I would log in to read them. When I wantedto look at my e-mail, my e-mail client would connect to the server machine. In the

simplest possible system, it would:

1. Ask the server to send a copy of the MBRAIN.TXT file2. Ask the server to erase and reset the MBRAIN.TXT file3. Save the MBRAIN.TXT file on my local machine4. Parse the file into the separate messages (using the word "From:" as the separator)5. Show me all of the message headers in a list

When I double-clicked on a message header, it would find that message in the text file

and show me its body. This is a very simple system. Surprisingly, the real e-mail systemthat you use every day is not much more complicated than this.

The Real E-mail System

For the vast majority of people right now, the real e-mail system consists of two different

servers running on a server machine. One is called the SMTP server, where SMTPstands for Simple Mail Transfer Protocol. The SMTP server handles outgoing mail. The

other is either a POP3 server or an IMAP server, both of which handle incoming mail.POP stands for Post Office Protocol, and IMAP stands for Internet Mail Access Protocol.


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A typical e-mail server looks like this:

The SMTP server listens on well-known port number 25, POP3 listens on port 110 and

IMAP uses port 143

Let's assume that I want to send a piece of e-mail. My e-mail ID is brain, and I have myaccount on howstuffworks.com. I want to send e-mail [email protected]. I

am using a stand-alone e-mail client like Outlook Express.

When I set up my account at howstuffworks, I told Outlook Express the name of the mailserver -- mail.howstuffworks.com. When I compose a message and press the Send

button, here is what happens:


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1. Outlook Express connects to the SMTP server at mail.howstuffworks.com usingport 25.

2. Outlook Express has a conversation with the SMTP server, telling the SMTPserver the address of the sender and the address of the recipient, as well as the

body of the message.

3. The SMTP server takes the "to" address ([email protected]) and breaks itinto two parts: The recipient name (jsmith)

The domain name (mindspring.com)

If the "to" address had been another user at howstuffworks.com, the SMTP serverwould simply hand the message to the POP3 server for howstuffworks.com (using

a little program called the delivery agent). Since the recipient is at anotherdomain, SMTP needs to communicate with that domain.

4. The SMTP server has a conversation with a Domain Name Server, or DNS (see

How Web Servers Workfor details). It says, "Can you give me the IP address ofthe SMTP server for mindspring.com?" The DNS replies with the one or more IP

addresses for the SMTP server(s) that Mindspring operates.5. The SMTP server at howstuffworks.com connects with the SMTP server at

Mindspring using port 25. It has the same simple text conversation that my e-mailclient had with the SMTP server for HowStuffWorks, and gives the message to

the Mindspring server. The Mindspring server recognizes that the domain namefor jsmith is at Mindspring, so it hands the message to Mindspring's POP3 server,

which puts the message in jsmith's mailbox.

If, for some reason, the SMTP server at HowStuffWorks cannot connect with the SMTP

server at Mindspring, then the message goes into a queue. The SMTP server on mostmachines uses a program called sendmail to do the actual sending, so this queue is called

the sendmail queue. Sendmail will periodically try to resend the messages in its queue.For example, it might retry every 15 minutes. After four hours, it will usually send you a

piece of mail that tells you there is some sort of problem. After five days, most sendmailconfigurations give up and return the mail to you undelivered.

THE WORLD WIDE WEB: (Access to information)Through keyword-driven Internet research using search engines, like Google,

millions worldwide have easy, instant access to a vast and diverse amount of onlineinformation.

Compared to encyclopedias and traditional libraries, the World Wide Web has enabled asudden and extreme decentralization of information and data.


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REMOTE ACCESS

The Internet allows computer users to connect to other computers and informationstores easily, wherever they may be across the world. This is encouraging new ways of

working from home, collaboration and information sharing in many industries.For example: An accountant sitting at home can audit the books of a company based in

another country, on a server situated in a third country that is remotely maintained by ITspecialists in a fourth. These accounts could have been created by home-working book-

keepers, in other remote locations, based on information e-mailed to them from offices all

over the world.

An office worker away from his desk, perhaps the other side of the world on a business

trip or a holiday, can open a remote desktop session into his normal office PC using asecure Virtual Private Network (VPN) connection via the Internet. This gives him

complete access to all his normal files and data, including e-mail and other applications,while he is away.

COLLABORATION

The low-cost and nearly instantaneous sharing of ideas, knowledge, and skills hasmade collaborative work dramatically easier. Not only can a group cheaply communicate

and test, but the wide reach of the Internet allows such groups to easily form in the firstplace, even among niche interests. An example of this is the free software movement in

software development which produced GNU and Linux from scratch and has taken overdevelopment of Mozilla and OpenOffice.org (formerly known as Netscape

Communicator and StarOffice).Messages can be sent and viewed even more quickly and conveniently than via e-mail.

Extension to these systems may allow files to be exchanged, 'whiteboard' drawings to be


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The pornography and gambling industries have both taken full advantage of the WorldWide Web, and often provide a significant source of advertising revenue for other Web

sites. Although many governments have attempted to put restrictions on both industries'use of the Internet, this has generally failed to stop their widespread popularity.

One main area of leisure on the Internet is multiplayer gaming. This form of leisurecreates communities, bringing people of all ages and origins to enjoy the fast-paced worldof multiplayer games. These range from MMORPG to first-person shooters, from role-

playing games to online gambling. This has revolutionized the way many people interactand spend their free time on the Internet.

Many use the Internet to access and download music, movies and other works for theirenjoyment and relaxation. Many use the World Wide Web to access news, weather and

sports reports, to plan and book holidays and to find out more about their random ideasand casual interests.

People use chat, messaging and email to make and stay in touch with friends worldwide,

sometimes in the same way as some previously had pen pals. Social networking Websites like Friends Reunited and many others like them also put and keep people in contact

for their enjoyment.

MARKETING

The Internet has also become a large market for companies; some of the biggestcompanies today have grown by taking advantage of the efficient nature of low-cost

advertising and commerce through the Internet; also known as e-commerce. It is thefastest way to spread information to a vast amount of people simultaneously.

The Internet has also subsequently revolutionized shoppingfor example; a person canorder a CD online and receive it in the mail within a couple of days, or download it

directly in some cases.

The Internet has also greatly facilitated personalized marketing which allows acompany to market a product to a specific person or a specific group of people more so

than any other advertising medium.Examples of personalized marketing include online communities such as MySpace,

Friendster, and others which thousands of Internet users join to advertise themselves andmake friends online. Many of these users are young teens and adolescents ranging from

13 to 25 years old. In turn, when they advertise themselves they advertise interests andhobbies, which online marketing companies can use as information as to what those users

will purchase online, and advertise their own companies' products to those users.

A very ineffective way of advertising on the internet is through spamming an email withadvertisements. This is ineffective because, now, most email providers offer protection

against email spam. Most spam messages are sent automatically to everybody in theemail database of the company/person that is spamming. This way of advertising is

almost like using adware. Adware is another ineffective way of advertising because mostpeople simply close a popup window when it shows up, not bothering to read it.


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FUTURE OF THE INTERNET

THE MOBILE INTERNET

The Internet can now be accessed virtually anywhere by numerous means. Mobile

phones, data-cards, and cellular routers allow users to connect to the Internet fromanywhere there is a cellular network supporting that device's technology.

BLOGS

One of the things that is so amazing about blogs is their simplicity. A blog is

normally a single page of entries. A blog is organized in reverse-chronological

order, from most recent entry to least recent. A blog is normally public -- the wholeworld can see it. The entries in a blog usually come from a single author.

A blog is a lot like an online journal or diary. The author can talk about anything

and everything. Many blogs are full of interesting links that the author has found. Blogsoften contain stories or little snippets of information that are interesting to the author.

Even though blogs can be completely free-form, many blogs have a focus. Forexample, if a blogger is interested in technology, the blogger might go to the Consumer

Electronics Show and post entries of the things he/she sees there.

In other words, a blog can be anything the author wants it to be.

Creating Your Own Blog

Creating your own blog is now easy because there are Web-based toolsets that makethe management of your blog incredibly simple -- Blogger, Xanga, TypePad, andLiveJournal are just a few of the services available. You can create basic blogs for free.

Creating a simple blog is free and only takes about five minutes. You enter your

name, e-mail address and a few other pieces of information. You select "the look"(template) for your blog from a set of standard templates. Click a few buttons and you're

done.

Now you can add new entries to your blog. Basically, all you do is type in the entry andpush the "post" button to post it. You can edit the entry as much as you like by clicking

the "edit" button. When you are happy with the new entry, you push the "publish" buttonto make your new entry visible on your public blog.

WEB 2.0 (refer video): Online collaboration with sharing data both by the user andby the website creator, Blogs, Vidoes, Photos, RSS Feeds and Online Applications today

have created a place where everything is possible. This is Web 2.0


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CREATING A WEB-PAGE

Web page - A Web page is a simple text file that contains not only text, but also a setofHTML tags that describe how the text should be formatted when a browser

displays it on the screen.

An HTML tag is a code element that tells the Web browser what to do with yourtext. Each tag will appear as letters or words between a < (less than sign) and a >

(greater than sign).

HTML - HTML stands for Hyper Text Markup Language. A "markup language" is

a computer language that describes how a page should be formatted.

Viewing Page Source : With your mouse, right-click on any blank portion of thispage and choose "View Source."

On your machine you have a program, or application, that can create simple text files.On Windows machines, this application is called Notepad.

Once you have the proper program open on your screen, type (or cut-and-paste) the

following HTML text into the window:

My First Page

Hello there. This is my first page!

Save it to the filename first.html.

Next, open the page in your Web browser. When you open it in your browser, it will looksomething like this:

Documents

Internet Notes by Systems)