Types of Computers

Mrs. Doss

TypesPersonal Computers (PC’S)

Used by a single user

Home or office

General computing tasks

Dell or Mac

DesktopDesigned to sit compactly on a desk

NotebookSmall, lightweight and designed for portability

TabletLightweight

Capable of recognizing ordinary handwriting on the screen

Cont…Hand-held Computers

Small

Fit in the palm of your hand

More capabilities than personal computers

Types of hand-heldPDA

Used for appointment book

Address book

Calculator

Notepad

MP3Used to store and play music

Cell phonesMake and receive calls

Store contact information

Internet capabilities

Cont…Mainframe Computers

Used by large businesses/government to provide centralized storage, processing and management for large amounts of data.

Very expensive- several million dollars

Supercomputers-Largest and fastest of all computers

Deal with tremendous volume of data

Cost tens of millions of dollars

Examples of Computer Types

ComponentsArchitecture

Design and construction of a computer

SpecificationsTechnical details about each hardware component

Example: a computer system might be configured to include a printer; a specification for that printer might be a print speed of eight pages per minute or the capacity to print in color.

Data Representation

Like a lightbulb, the computer must interpret every signal as either “on” or “off.” To do this, a computer represents data as distinct or separate numbers. It represents “on” with a 1 and “off” with a 0. These numbers are referred to as binary digits.

ByteSeries of 8 bits

Kilobyte (KB)- 1024 bytes

Megabyte (MB)- 1 million bytes

Gigabyte (GB)- 1 billion bytes

Terabyte (TB)- 1 trillion bytes

Understanding Memory

RAMTemporarily holds programs and data while the computer is on.

Cache memoryHigh speed memory chip on the motherboard

Stores frequently accessed and recently accessed data

Virtual memorySimulates additional RAM

Enable programs to run as if your computer had more RAM by moving data and commands from RAM.

Much slower than RAM

Cont…Read-only memory

Chip on the motherboard that has been prerecorded with data

ROM PERMANETELY stores the set of instructions that the computer uses to check to the computer system’s components to make sure they are working.

ROM never changes and remains intact when the computer is off; therefore, it is called PERMANENT MEMORY

STORAGE MEDIACOMPUTER FILE-

Named collection of stored data

EXECUTABLE FILEContains the instructions that tell a computer how to perform a certain task.

Example: files that are used when the computer starts.

DATA FILE-Created by the user, usually with software.

Example- a report that you typed in word to access later.

Cont…MAGNETIC STORAGE MEDIA

Store data as magnetized particles on a surface

HARD DISK IS THE MOST COMMON TYPE

OPTICAL STORAGE DEVICESDiscs coated with a reflective metal on which data is store using laser technology.

Examples: CD, DVD, Blu-Ray

FLASH MEMORYSmall, portable cards encased in hard plastic

Can be written and re-written

Example: USB Flash Drive

NetworksNetwork

Connects one computer to other computers and devices, enabling you to share data and resources with others.

Network interface cardCreates a communication channel between the computer and network

Network softwareEstablishes the communication protocols

Controls “traffic flow” of data

ServerAct as the central storage location for programs

Provide mass storage for most of the data used on the network.

Cont….LAN- LOCAL AREA NETWORK

Computers and devices are located close to each other

Same building

WAN- WIDE AREA NETWORKMore than one LAN connected together

Internet is the largest WAN

WLAN- WIRELESS LOCAL AREA NETWORKUse Wi-Fi to communicate and connect in a network

Security ThreatsSecurity

The steps a computer owner takes to prevent unauthorized use of or damage to the computer.

Types of SecurityMalware- describes any program that is intended to cause harm or convey information to others.

Viruses- instruct your computer to perform destructive activities, such as erasing a hard drive.

Spyware- track a computer user’s Internet usage and send this data back to the company or person who created it.

Cont…Firewall- like a locked door on your computer. Prevents other computers on the Internet from accessing your computer.

Phishing- sending e-mails to customers of a legitimate website asking them to click a link in an e-mail. If the customer clicks the link the browser will go to a site so the company can get personal information.

System SoftwareHelps the computer carry out its basic operating tasks.

Four types of system software:Operating system

Allocates system resources

Manages storage space

Maintains security

Detects equipment failure

Controls basic input and output

Utilities:Augment the operating system by taking over some of its responsibility for allocating hardware resources.

Device DriversHandle the transmission protocol between a computer and its peripherals.

Cont…Programming Languages:

A programmer uses these to write computer instructions.

The instructions are translated into electrical signals that the computer can manipulate and process.

Application Software

• Enables you to perform specific computer tasks

• Embedding- occurs when you copy and paste the source data in the new file.

• Linking- allows you to create a connection between the source data and the copy in the new file.

• These are also referred to as OLE

Cont..Document production software

Word processing software, desktop publishing software, email editors.(EX: Word)

Spreadsheet software-Numerical analysis tool

Creates a worksheet comprised of a grid of columns and rows. (EX: Excel)

Database management software- lets you collect and manage data (EX: Filemaker Pro)

Cont…Graphics and Presentation software:

Allows you to create illustrations, diagrams, graphs and charts that can be projected. (EX: PowerPoint)

Photo-editing Software-Allows you to manipulate digital photos (EX: Photoshop)