Computer

•What are telecommunication ?
•This term refers to transmission of information over long distances using the telephone system , radio , TV , satellite or computer links. in the modern world , telecommucitaions mainly means transferring information from one PC to another via modem and phone lines ( or fiber optic cables ).

•What can you do with modem ?
•A modem is your computer’s link to external world.•What do you need to telecommunicate ?
•You just need PC ( or terminal ) , a modem connected to the computer and the telephone line , and communication software .

•Local bulletin boards
•Bulletin board system (BBS) are frequenly free because they are run enthusiasts and sponsored by user groups or small business. You can use BBS to download artwork, games and programs or you can paricipate in ongoing discussions. You can also upload ( send ) program.
•Online service provider
•To gain access to the internet you must first open an account with an internet sevice provider (ISP ) or commercial online service provider

Try to answer these questions
•1. How can a PC be connected to another computer ?
•2. What data communication systems can you think of ? make a list.
Observe the following words below and give description •Fax
•MODEM
•Concentrator
•Electronic mail ( e- mail )
•Teletext
•Internet service provider ( ISP )
•Comercial online service


SECURITY AND PRIVACY ON THE INTERNET
There are a lot of benefits from an open system like internet , but we are also exposed to hackers who break into computer system just for fun, as well as to steal information or propagate viruses. So how do you go about making online transactions secure ?

Security on the web
The question of security is crucial when sending confidential information such as credit card numbers. For example , consider the process of buying a book on the web. You have to type your credit card number into an order form which passes from computer to computer on its way to the online bookstore , if one of the intermediary computers is infiltrated by hackers, your data can be copied. It is difficult to say how often this happens , but it’s technically possible.

E – mail privacy
Similarly , as your e- mail message travels across the net, it is copied temporarily on many computers in between. This means it can be read by unscrupulous people who illegally enter computer systems.



Network security
Private networks connected to the internet can be attacked by intruders who attempt to take valuable information such as social security numbers , bank accounts or research and business reports.

Virus protection
Viruses can enter PC through files from disks ,the internet or bulletin board system, don’t open e-mail attachments from strangers and take care when downloading files from the web.

Try to answer these questions
1.Why security so important on the internet ?
2.What security features are offered by nescape Communicator and internet explorer ?
3.What security standard is used by most banks to make online transaction secure ?
4.How can we protected and keep our e-mail private ?
5.What method are used by companies to take internal networks secure ?
6.Which way can virus enter a computer system ?
7.What is a hacker ?