1. NETWORK COMPUTER

Networks are collections of computers, software, and hardware that are all connected to help their users work together. A network connects computers by means of cabling systems, specialized software, and devices that manage data traffic. A network enables users to share files and resources, such as printers, as well as send messages electronically (e-mail) to each other.
Computer networks fall into two main types: client/server networks and peer-to-peer networks. A client/server network uses one or more dedicated machines (the server) to share the files, printers, and applications. A peer-to-peer network allows any user to share files with any other user and doesn’t require a central, dedicated server.
The most common networks are Local Area Networks or LANs for short. A LAN connects computers within a single geographical location, such as one office building, office suite, or home. By contrast, Wide Area Networks (WANs) span different cities or even countries, using phone lines or satellite links.
Networks are often categorized in other ways, too. You can refer to a network by what sort of circuit boards the computers use to link to each other – Ethernet and Token-Ring are the most popular choices. You can also refer to a network by how it packages data for transmission across the cable, with terms such as TCP/IP (Transmission Control Protocol/Internet Protocol) andIPX/SPX (Internet Package eXchnage/Sequenced Package eXchange)

OPERATING SYSTEMS VERSUS APPLICATION SOFTWARE

An operating system (OS) is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system. A user cannot run an application program on the computer without an operating system, unless the application program is self booting.

Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting for cost allocation of processor time, mass storage, printing, and other resources.

For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between application programs and the computer hardware,^[1][2] although the application code is usually executed directly by the hardware and will frequently call the OS or be interrupted by it. Operating systems are found on almost any device that contains a computer—from cellular phones and video game consoles to supercomputers and web servers.

APPLICATION SOFTWARE

(1) Application software is the general designation of computer programs for performing user tasks. Application software may be general purpose (word processing, web browsers, ...) or have a specific purpose (accounting, truck scheduling, ...). Application software contrasts with (2} system software, a generic term referring to the computer programs used to start and run computer systems and networks; and (3) programming tools, such as compilers and linkers, used to translate and combine computer program source code and libraries into executable programs (programs that will belong to one of the three said categories).

WORD SOFTWARE  

FUNCTIONS =used ducuments such as compaosing editing,formating, and printing

EXAPLE       =microsoft wird 2007,notepad .

SPREADSHEET

FUNCTIONS =freequently used for financial information because of their ability to calculate data automaticaly 

EXAMPLE    =microsoft Excel 2007 ,visicalc 

PRESENTATION

FUCNTIONS =used for present informations to the audience 

EXAMPLE    =microsoft powerpoint 2007,apple keynote ,corel prensentions

WEB BROWSER

FUCNTION =used for retrieving,presenting,and traversing information resoursces on the world wide web

EXAMPLE  =internet explorer 9,mozilla ,google chrome