Computer Skills

Preparatory Year

2011-2012

Presented by:L.Obead Alhadreti

Last week - Lecture 3 The main parts of the Personal Computer Computer Software Types of Computer Software Software/System Development Process

Lecture 4 - Outline Networks and their advantages Networks Types Client and Server The Internet The Intranet & Extranet Main uses of the Internet Internet Connection

Networks and their advantages

Network DefinitionThe network can be defined as a collection of computer

connected

together with an objective of sharing resources.

Networks Advantages: Sharing hardware components e.g. printer Sharing computers software e.g. programs by using

servers. Sharing Information by joining files and folders through the

network. Protecting data and information by using a username and

password.

Networks Types

Networks Types:The network, according to the distance between the computer

can be divided

Into:

1. Local Area Network (LAN) is a group of computers connected to each other

by cables, distributed in a limited areas e.g. a company.

Networks Types

2. Wide Area Network (WAN) is a group of computers connected to each other

but for being distributed in a wide areas e.g. branches

of company in two city. Communication is done through

telephone lines or satellites.

3. Metropolitan Area Network (MAN) is a group of computers connected to each other

but for being distributed all over a city.

Client and Server

Client a computer connected to the network. Has no authorities

in relation to the network. Only use the

services introduced by the server.

Server a computer provides services to the clients and control the

network .

The Internet

The network, according to the user access can be divided into:

The definition of the Internet is a collection of various networks that can communicate

with one

another.

International Network = Internet

internet is a network which is for public.

The communication between the computers is done through a protocol

called Transmission Control Protocol/ Internet Protocol (TCP/IP).

The Internet

The history of the Internet It all begins during the cold war between the soviet union

and the united states.

-1957 the soviet union developed a satellite to transfer information.

- 1960 ARPA developed ARPA net.

- 1969 ARPA net was connected to many American universities.

- 1970 The internet was used in Europe.

- 1972 electronic email appeared.

- 1980 the internet was widely used.

The Intranet & Extranet

The Intranet is an internal and local network. Used the technology of

internet in an isolated environment. e.g. A special network for the company to exchange information and data , used only by the staff. Used firewall to protect the data. Users need username and password to log ii.

The Extranet is expanded local network.. grant some of the clients the

capabilities to use them through secure gates. A collection of intranet networks. e.g. bank to view our bank statement.

Main uses of the Internet

The world wide web (WWW) is the most common service. Developed in 1992. by tim

breners.

it is a huge hyper text documents. Depends on a protocol

called Hyper Text Transfer Protocol (HTTP).

Used to get information in various forms, e.g. sound, visual, and

written form.

The advantages of www pages Non-linearity Interactivity Grpahical interfaces

Main uses of the Internet

The electronic mail (e-mail) is one of the most commonly used application.

Is an electronic copy of the ordinary mail. It is free.

Developed in 1972. used to send messages anywhere in

the world. Used a protocol called SMTP.

User-name@ server-name

Example: AAA@ hotmail.com

Main uses of the Internet

File Transfer (FTP)Enable its users to upload and download the files, which help

researcher to

transfer data through the network. Used File transfer protocol (FTP).

Internet relay chatEnables its users to chat with one another. Can be done by

writing, sound,

pictures, videos. It assist in distance learning.

Internet Connection

To connect to the Internet, you will need to:1. TCP/IP2. Connection unit e.g. Modem3. Communication lines4. Internet services provider (ISP)5. Internet browser e.g. Internet explorer.

Types of Communication lines

1. PSDN PSDN or Public Switched Data Network is simply the

technical name for the telephone system in use today.

2. ISDN Stands for "Integrated Services Digital Network." ISDN

dates back to 1984, and allows much faster transfer rates than when using modems. Using ISDN, you can transfer 64K or 128K of data per second.

3. Satellites Satellite communications makes it possible for you to make

a telephone callor access the internet from almost anywhere on the planet.

Very Expensive.

Modem Modem

is advice that transform the analog signals

into digital signals and vice versa. The computer deals with the digital signals while the telephone lines deals with the analog signals. The modem sends information from your computer across the telephone system. The modem at the other end of the phone line, converts the signal back into a format that can be used by the receiving computer.

Lecture 4 - Outline Networks and their advantages Networks Types Client and Server The Internet The Intranet & Extranet Main uses of the Internet Internet Connection

Lecture 5- Next Week ! IT in society