IT internet security

The Internet The Internet - a physical collection of many networks worldwide which is referred to in two ways: The internet (lowercase i) is any collection of separate physical networks, interconnected by a common protocol to form a single logical network The Internet (uppercase I) is the worldwide collection of interconnected networks that uses Internet Protocol (IP) to link the various physical networks into a single logical network

The World Wide Web A network of information contained in web pages which are found and viewed by using web browser programs eg Internet Explorer or Netscape Technically, the World Wide Web is all the resources and users on the Internet that are using the Hypertext Transfer Protocol (HTTP) It links pages and sites together using hypertext links The web is not the same as the Internet. It is just part of it, and only one of several Internet environments Others include , Internet Relay Chat, FTP (File transfer Protocol), and Usenet news groups

Browser A software application used to navigate the www to locate and display Web pages eg Explorer A World Wide Web access program that requests documents or other files from a web server, and displays them on a user's display device

Intranet A private network of computers within an organization used to share information and computing resources It sits behind a firewall and is only accessible to people who are members of the same organization, using passwords and logins Uses regular Internet protocols and looks like a private version of the Internet

Extranet It is an intranet that is partially accessible to authorized outsiders You can only access an extranet if you have a valid username and password, and your identity determines which parts of the extranet you can access

Viruses Self-replicating programs that spread by inserting copies of itself into executable code or documents Can only spread from one computer to another when its host is taken to the uninfected computer, eg sending it over a network or carrying it on a removable disk May cause a simple prank that pops up a message May destroy programs and data right away or on a certain date Can lie dormant and do its damage once a year. eg the Michaelangelo virus contaminates the machine on Michaelangelo's birthday

Worms A computer worm is a self-replicating computer program, similar to a computer virus It is self-contained and does not need to be part of another program or attach itself to other files or programs to spread itself It may be designed to do any number of things, eg delete files or send documents via or carry other executables as a payload It can spread itself automatically over the network from one computer to the next

Trojans Trojan horse is a program in which harmful code is contained inside apparently harmless program or data so that it can get control and cause damage

Hoaxes Hoaxes may seem harmless, but they do a great deal of damage to the Internet as a whole Not only do they slow down traffic and clog up servers, but they also cause people to panic

Phishing A form of identity theft an is sent that looks like it comes from a legitimate company (eg E-Bay) telling you that you must update your records and verify your username and password The site is really a fraud which captures your information to steal your identity, money, or whatever

Spam The Internet version of junk mail Over 50% of all s today are junk Spamming is sending the same message to a large number of mailing lists or newsgroups without consent The term probably comes from a famous Monty Python skit Often used to carry viruses, worms etc

Spyware (or Adware) Program that secretly monitors your actions on your computer without your permission Sends this information to someone else Some are sinister and gather information about addresses, passwords and credit cards Some are used by software companies to gather data about customers