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Unit 1 – Internet Basics
Presentation 4
Web Programming
Objectives
At the end of this presentation, you will be able to
• Use the browser
• Discuss about Web server
• Discuss about data transfer from client to server.
• Identify parts of IP address and URL.
The Browser
• Software that acts as an interface between the user and the Web.
• Resides in the client machine.
• Reads the instructions given in a language such as HTML and displays the document in the browser window.
The Browser
• Eg. Internet Explorer, Netscape Navigator, Hot Java, Mozilla, Mosaic and Opera.
The Internet Explorer
• To open the Internet Explorer select Start Programs Internet Explorer.
• Title bar is displayed at the top
The Internet Explorer
• Menu bar is displayed below the title bar.
• Below the Menu bar is the Standard Buttons toolbar.
The Internet Explorer
• Next to the Standard Buttons toolbar is the Address bar. The URL of a Web page is typed here.
• Below the address bar is the area where the document will be displayed.
The Internet Explorer
• Below the address bar is the area where the document will be displayed.
• The status bar is displayed at the bottom of the Internet Explorer window.
Opening a Web page
• Type the URL of the Web page in the Address bar.
• Press the Enter key.
• Eg. Open yahoo.com by typing www.yahoo.com in the Address bar and press the Enter key.
Buttons in the Standard buttons toolbar
- To open the previous page that had been visited.
- To open the next page to the current page that had been visited.
- To stop the search in the middle.
- To restart the search from the beginning.
Buttons in the Standard buttons toolbar
- Web pages that you often visit can be stored in Favorites.
- Clicked to get back to the home page set in the browser.
Web Server
• Client computer makes request.• Server Computer responds to client’s request.• Some of the servers are Web server, FTP
server and mail server.• Web server follows a set of rules while
communicating with the client known as HTTP (Hypertext Transfer Protocol).
Steps that occur while opening a Web page
1. Browser breaks the URL into different parts namely, the protocol (HTTP – Hypertext Transfer Protocol), the server name and the file name.
Protocol
Server Name
http://www.geographia.com/indx04.htm
File Name
Steps that occur while opening a Web page
• Sends the server name to a name server.
• Name server translates Server name into IP address.
Steps that occur while opening a Web page
• Sends the server name to a name server.
• Browser uses Server name and sends a GET request to the server asking for the Web page.
Steps that occur while opening a Web page
• Server finds the requested page and sends HTML code of the page to the browser.
• Browser reads the HTML code and displays the page in the browser window.
Data Transmission in the Internet
IP Address
• Computer in the network is identified by a unique address known as IP address.
• It contains four parts each called octet. • Each octet made up of 8 bits (8 binary
digits) and makes a total of 4 X 8 = 32 bits.
103.38.123.214
Represents a network
Represents a specific computer in the network
IP Address
• Each octet is a number between 0 and 255 in decimal form and is separated by a dot.
• First 3 octets represent the network to which the computer is connected.
• Fourth octet represents the computer in that network.
103.38.123.214
Represents a network
Represents a specific computer in the network
URL
• Every Web page in WWW has a unique address called as URL
• Similar to the postal address. • URL contains protocol, domain name, path
and Web page name.
Protocol
Server Name
http://www.geographia.com/indx04.htm
File Name
URL
• Last portion in the domain name is called top-level domain that represents the type of organization, the Web site belongs to.
Top-Level Domains
Domain Type
com Commercial Organizations and companies
org Non-Profit Organizations
net Company that provides network
gov Government Organizations
edu Educational Institutions
Summary
In this presentation, you learnt the following:• Open the Internet Explorer by selecting
Start Programs Internet Explorer • Browser is an application program that
displays the content of a web Page.• Some of the servers are Web server, FTP
server and mail server.
Summary
In this presentation, you learnt the following:• Each computer in the network is identified
by a unique address known as IP address.• Every Web page in WWW has a unique
address called as URL.
Assignment
1. Write how to open Internet Explorer.
2. Define Web browser.
3. Give some examples of Web browser.
4. Name the different parts of a URL.
5. Define IP Address.
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