Computer System Components and Data Storage Definitions

Computer Hardware and Software Fundamentals

Defining Hardware

Hardware is used to describe the physical parts of a computer system that you can touch. Examples include monitors, keyboards, printers, hard drives, wiring, the CPU, etc.

Essential Hardware Components

The following are key components of a computer system:

• Keyboard

  A tool used for typing, similar to a typewriter.

• Monitor

  The screen on your computer that you look at when you are using the computer.

• Mouse

  A piece of plastic input device. Older models typically had a ball on the bottom and two buttons on the top. When you click the mouse, you usually use the left button. It allows you to click on and select items on your screen.

• Printer

  A machine that transfers data from the computer onto paper.

• Scanner

  A piece of equipment that copies pictures or documents so that you can use them in your computer projects.

• Speakers

  The part of the computer system that allows you to hear sounds from programs.

• Modem

  A device that connects the computer to phone lines (or other communication lines) to access the Internet.

Internal Components and Processing

Chip

A small component inside the computer that helps it function. Chips must be programmed by people to function. There are many chips in a computer.

Motherboard

The main circuit board (PCB) of the computer that holds many chips. The motherboard enables the computer to work. It is also where the memory and the processing components are located.

CPU (Central Processing Unit)

A chip that is the "brains" of your computer, processing information. The CPU is made up of the Control Unit, Memory, and the Arithmetic Logic Unit (ALU).

Processor

An electronic circuit that can execute programs, store information, or perform calculations. It is often called "the brain of the computer."

Memory and Storage Media

RAM (Random Access Memory)

Information in RAM can be read and written quickly in any order. This type of memory is used while the PC is running. This data is usually lost when the computer is switched off (volatile memory).

ROM (Read-Only Memory)

ROM is a memory chip where essential system instructions are permanently stored. It holds information needed by the PC and cannot typically be changed.

Hard Drive

A primary storage device that has a lot of memory to save your work.

Disk

A piece of plastic that holds information for or from your computer.

CD (Compact Disc) Types

A round disc that holds information for or from your computer.

• CD-ROM (CD-Read Only Memory)
• CD-R (CD-Recordable)
• CD-RW (CD-ReWritable)

Floppy Disk (Diskette)

A magnetic storage medium that typically holds about 1.44 MB of data. It is protected by a rigid plastic square. It is useful for storing small files.

Pen Drive (Flash Drive)

Connects to the computer through the USB port. It is used to transport files and back up data between computers.

Data Measurement Units

• 1024 Bytes = 1 Kilobyte (KB)
• 1024 KB = 1 Megabyte (MB)
• 1024 MB = 1 Gigabyte (GB)
• 1024 GB = 1 Terabyte (TB)

Understanding Software

Software includes all computer applications and operating systems used with the computer system. Software instructs the hardware on how to perform specific tasks.