Types of Computers Mrs. Doss
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)