07-04-2012, 02:57 PM
Internet Works
HowtheInternet.ppt (Size: 122 KB / Downloads: 134)
The World Wide Web is the most popular part of the Internet by far. The Web allows rich and diverse communication by displaying text, graphics, animation, photos, sound and video. The Web physically consists of your personal computer, web browser software, a connection to an Internet Service Provider, computers called servers that host digital data, and routers and switches to direct the flow of information.
Components of the Internet
The Internet is comprised of many components such a Email, FTP and Usenet News. The World Wide Web is simply one of these components.
World Wide Web (World Wide Web is like an Internet Library with millions of books)
FTP
E-mail & E-mail Discussion Groups
Telnet
Usenet News
HTTP
Chat & Instant Messenging
What is Hypertext
Hypertext is a method of presenting information, where selected words in text can be expanded at any time to provide other information about the word. Those words are links to other documents which may be text, file, pictures etc., Links can be identified by highlighted (underlined) and coloured text.
Web Browsers
Common Web Browsers
Mosaic – first graphical browser
Netscape Navigator (First commercial browser, originally known as Mosaic Navigator as originated from Mosaic)
Internet Explorer (Microsoft’s browser)
Lynx – text only browser
Common Errors with Browsers
Server Does Not Have A DNS Entry
503 Service Unavailable
403.9 Access Forbidden – Too Many Users are Connected
Spinning Hourglass
404 Not Found
401 Unauthorised and 402 Forbidden
Encryption for E-Mail Privacy
Public & Private Keys most common form of encryption
How E-Mail Spam Works
Spam is Unsolicitied Junk E-mail
Blocking Spam
Write back to Spammer and asked to be removed
E-mail Software filters e-mail addresses
ISP like AOL block spammers from sending bulk mail to subscribers
IRC - Internet Relay Chat
Unlike AOL IM and ICQ, IRC (Internet Relay Chat) is not owned by any company. To use IRC, you need an IRC client program.
IRC has many networks that are completely separate from one another. Some popular networks include The Undernet, EFnet, and DALnet. If you want to chat with someone on IRC, you need to make sure that both of you are on the same network (you can set it and change it each time your start your IRC program.)
IRC has very few rules. You are allowed to say pretty much anything to want to pretty much anyone you want. For example, if you are on AOL, and someone keeps bothering you, you could report that screen name to the AOL company. There is no high authority on IRC, but there is still an ignore option to use if someone annoys you.