F451 - 3.1.1 Components of a Computer System

Hardware
- Physical components that make up a computer system

Software
- The computer programs/instructions that tell the computer what to do

Input Device
- Hardware that allows data to be entered into a computer

Storage Device
- Hardware that allows data to be saved/stored, long-term, after it has been inputted into a computer for future use

Output Device
- Hardware that presents data from the system to the user

INPUT DEVICE
- Gives the computer the data to be used when instructions are carried out
Examples:
- Barcode reader (to read barcode of an item)
- Keyboard (to input damaged barcode/amount paid)

STORAGE DEVICE
- Needed to store files when the power to the processor is switched off
- Needed to store files which are too big to be stored in the procesor
Examples:
- Hard Disk Drive, CD-ROM, USB Memory Stick

OUTPUT DEVICE
- Needed so that the computer can report to us what it has done
- Needed as it affects future input in the system
Examples:
- Printer (to give a hard copy output for customers)
- LCD Screen (to show details and price of current items)
- Beeper (to signify barcode has been properly read)
- Chip and Pin (to input payment details) 

SYSTEMS SOFTWARE
- Controls the operation of hardware and provides a platform to run other software

APPLICATIONS SOFTWARE
- Allows the user to do something useful with the computer

Examples:
Word Processor, Spreadsheet, Desktop Publishing Package, Presentation Software, Web Authoring, Database.

Write Letters: Word Processor

Produce business accounts: Spreadsheet

Produce instruction manual: Desktop Publisher

Produce website: Web authoring

Store customer records: Database