Introduction to Computers

What is a computer?computer

What does a computer do? Power of a Computer Speed Reliability Bits and Bytes Accuracy Storage Process Output Storage Input Raw Data Information

Computer Components

CPU – Central Processing Unit Control Unit and Arithmetic /Logic Unit Memory - –ROM Read Only BIOS Remains on power off –RAM Random access Empties on shut off

Input Devices Keyboard Mouse Magnetic Card Scanner Stylus Touch Screen Card Scan Biometric

Out Put Devices Monitor –CRT –LCD Printer –Impact / dot matrix –Inkjet –Laser Speaker

Computer Storage Floppy Disk – 1.4 MB Hard Disk - GigabytesGigabytes CD –CD ROM, CD-R, CD-RW –650 MB DVD – GB

Data Size Bit1,0 Byte = 1 character KilobyteKilobyte - KB1000 bytes MegabyteMegabyte - MB1million bytes GigabyteGigabyte – GB1 billion bytes

Memory RAM – random access memoryRAM –Stores information temporarily –Like the desktop or workbench –Data is erased on powerdown ROM – read only memoryROM –In the CPU and other places –Remains the same – rarely changed –Remains upon powerdown

Software System Software – controls the operation of the computer Must boot up to start – loads operating system into memory GUI – graphical user interfaceGUI –DOS –Windows, 3.11, 98, ME, XP, XP Pro, 2000

Application Software Application Software – software that tells the computer how to produce information –office –games –finance –diagnostic – business –utilities – anti virus, pop up blockers, etc.

Word Processing Software MS Word, Corel… For working with text Easy to make changes / corrections Combines with other software

Spreadsheet Software Calculations Charts Eliminates recalculation MS Excel

Database Software Stores Data of all kinds for easy access MS Access, Schoolmaster, Produces reports of the information Law Enforcement

Networks and the Internet Network –Computers linked together –Sharing of hardware, software, data, information LAN – local area networkLAN WAN – wide area networkWAN Internet

Internet / WWWWWW World’s largest network Web Pages Web Site URL – uniform resource locator – unique addressURL