Computer Fundamentals: Hardware, Types, and Network Components

Computer

Machine that uses electronic components and instructions to perform calculations and repetitive and complex procedures, process texts, and manipulate data and signals.

Computer Hardware

All of the physical components of the machine itself.

Motherboard

Thin, flat sheet made of a firm, non-conducting material on which the internal components (printed circuits, chips, slots, etc.) of the computer is mounted.

Central Processing Unit (CPU)

Brains of the computer, consisting of at least one arithmetic and logic unit, a control unit, and memory.

Arithmetic and Logic Unit

Controls mathematic functions and functions that test logic conditions.

Control Unit

Carries out the machine language functions called fetch, execute, decode, and store.

Memory

Includes the locations of computer's internal and main working storage.

Read Only Memory (ROM)

Permanent storage where data and programs can only be read by the computer and cannot be erased or altered.

Random Access Memory (RAM)

Working memory that is changeable and temporary, can be accessed, used, changed and written on repeatedly.

Input Device

Allow the computer to receive information from the outside world.

Mouse

Hand controlled mechanical device that electronically instructs the cursor to move across the video display screen.

Keyboard

Most common input device, similar to keyboard of typewriter.

Touch Screen

Involves use of a special filter on a monitor screen that allows the screen to sense the pressure of the user's finger on a particular position on the screen.

Light Pen

Photosensitive device that responds to light images when placed against a monitor screen.

Optical Character Recognition

Specialized computer input medium that allows data to be read directly from a form or document.

Voice/Speech Synthesizer

Allows user to input data into the computer by speaking into a connected microphone.

Output Device

Allow the computer to report its result to the external world.

Monitor

Display screen component of a terminal that allows the user to see images, programs, commands the user sends to the computer, and results of computer's work.

Printer

Most important output device that converts information produced by the computer system into printed form.

Storage Media

Includes the main memory but also the external devices on which the programs and data are stored.

Hard Drive

Peripheral that has a very high speed and high density, a very fast means of storing and retrieving data.

Diskettes

Allows input and output from a diskette, which is a round magnetic disk encased in a flexible or rigid case.

CD ROM

A rigid disk that holds a much higher density of information than a diskette and has a much higher speed.

USB Disk

Form of a small, removable hard drive that is inserted into the port of the computer.

First Generation Computers

First true digital computer (Colossus Mark I) was made in 1943.

Second Generation Computer

Introduced in the late 1950s, included IBM 1401 and 1620, used transistors instead of vacuum tubes.

Third Generation Computer

Introduced in mid 1960s, used micro-miniature solid state components.

Fourth Generation Computers

Introduced by IBM, IBM 370, first mainframe family that had printed circuits.

Analog Computer

Operates on continuous physical or electronic magnitudes, measuring ongoing continuous analog quantities such as voltage, current, temperature, and pressure.

Digital Computer

Operates on discrete discontinuous numerical digits using the binary system.

Hybrid Computer

Contains features of both analog and digital computers.

Supercomputers

Largest type of computer, specifically designed for scientific applications requiring gigantic amounts of calculations.

Mainframes

Fastest, largest, and most expensive type of computer used in corporate America for processing, storing, and retrieving data.

Microcomputer (Personal Computer / PC)

Used for a number of independent applications as well as serving as a desktop link to the programs of the mainframe.

Handheld Computers

Small, special function computers.

Network

A set of cooperative interconnected computers for the purpose of information interchange.

LAN

Usually supports the interconnected computer needs of a single company or agency.

WAN

Supports geographically dispersed facilities.

Network Hardware

Provide interconnection between computers.

Network adapter or Network interface card

Computer circuit or card that is installed in a computer so that it will be connected to a network.

Communication Medium (Cabling)

Means by which actual transfer of data from one site to another takes place.

ISDN (Integrated Services Digital Network)

Used to carry communications across phone lines.

Bandwidth

Controls how fast the signals can be transmitted across phone lines.

DS0

The first digital standard that transmitted at 64 kilobytes per second.

T-Lines

Replace DS0 and are used to handle the high speed transmission needed for network communications.

Servers

Computer program that provides services to other computer programs in the same computer or in other networks.

Client-server approach

One computer is the core or server computer that receives requests from the client computer and fulfills those requests.

Architecture

Refers to overall physical structure, peripherals, interconnections within the computer, and its software system.

Five fundamental components (Computer Subsystem)

Input/Output, Storage, Communication, Control, Processing.

Broadcast

Communication is done by transmitting the same information to all computers in the network.

Point-to-Point

Used in dial up networking.

Topology

Defines how the network computers in LAN are interconnected within a physical area.

Bus

Network topology or circuit arrangement in which all the node computers are directly attached to a line.

Star

Centralized structure where all computers are connected through a central computer (server).

Ring

Connection with wires or cables that directly connects computers together.

Hub

Consists of backbone or main circuit attached to outgoing lines.

Arcnet

Token bus system for managing line sharing among all users on the network.