Internet
• a wide area network spanning the globe.
• consists of many smaller networks linked together.
Service
• a way of using the internet to perform specific tasks
Three main services:
World Wide Webgives access to information in remote computers through browsing or searching
Emailmessages between computers
File transferto send or receive large files
Other services
Chata web site where users can take part in text discussions with other users
Instant messaginga program that looks for your friends online and tells you that they can receive messages
Bulletin boards (forums)an electronic notice board where users can post, read, look at messages
Discussion groupgeographically separated users with a common interest hosted on a web site
Web logs a web page made up of short entries in chronological (time) order like a diary
On-line banking
On-line shopping
Video streamingthe process of receiving video images over a network and displaying them on a computer screen
Video Conferencinguses communication links to conduct meetings between people who are geographically separated. Requires a computer system and a webcam in each location together with a network connection
To connect to the Internet you need:
computer system
modem
communications software eg. browser and email client program
Internet Service Provider (ISP)
Internet Service Provider (ISP)
A company that provides a host computer connected to the Internet which the user can access. The host computer manages communications and stores data such as email and web pages
Modem
a piece of hardware that changes the digital signals from a computer into “telephone signals” which can be sent along a normal telephone line. A modem at the other end changes the signals back into digital form for the receiving computer.
Internet ready computer – consists of:
• computer system
• internal modem
• communications software eg. browser and email client program
Mobile Internet Technologies
Includes palmtops, laptops, mobile phones.
Do not need a mains power supply or physical connection to the Internet, which can be achieved using wireless networking interface cards.
Dial-up connection
a wire connects the computer’s modem socket to the telephone socket. The communication software dials the ISP’s number and establishes a connection to the Internet.
Broadband connection
constantly connected to the Internet, much faster access. Telephone can be used at same time. More than one computer can be connected to Internet at same time.
Downloading Software
Downloading
Receiving a file from a network (server or individual computer) and saving it onto a computer system.
Freeware
Totally free software that can be used on any number of computer systems.
Downloading Software
Shareware
Free for a short trial period to let you try it. After that you must either delete the software or pay to continue using it. Some crucial functions usually missing (e.g. save, print).
Commercial software
Must be paid for. Can only be used on one computer without a special license. You cannot legally make copies.
Browser
• a program that allows the user to access web pages (surf the net) eg. Internet Explorer
Web page
• a single document or file on the World Wide Web
• identified by a unique URL (Universal Resource Locator)
• can used to hold information in multimedia form
World Wide Web
Hyperlink
Links Web pages, documents or files; activated by clicking with the mouse.
HTML
Hypertext mark-up language. A special language used to create Web pages.
Search Engine
A site designed to help you find information. The user can enter keywords.
Simple Search
The user enters one or more keywords
Complex Search
Allows the user to refine a search by restricting the search to only parts of the Web. Most allow the use of AND ( +), OR, NOT ( - ) eg. mountain + scotland
The Big Bad World Wide Web
Is inhabited by?
Who controls it?
Who checks the information is correct?
Who has access•to the WWW?•to your data on the WWW?
Creating a web page
Simplest way is to use• a wizard or• a template
You can then • enter your text• add graphics
Creating a better web page
To create a more interesting page, add
• audio• video• hyperlinks using text or hotspots (A
defined area in a graphic containing a hyperlink)
Present information using tables