Information System

An information system is a system which accepts data as an input and gives information as a output. The input of data can also be a system and the system can be a sub-system of a larger system so systems are generally realated to each other in some way. Systems can be represented by context diagrams, block diagrams and data flow diagrams.

Contents of an Information System
An information system consists of several parts.

Environment
This is the space in which the system operates, and where it receives (and sometimes transmits) its data. It can also include other information systems that interact with the main information system.

Purpose
This is the reason for the system's being, its main job.

Information Processes
There are several of these. They are the actions which the information system executes to complete its task. A helpful mnemonic to remember this is 'Can Old Alfie Still Remember Polly's Toy Rubber Doggie?' Childish, but it does work.
 * Collecting
 * Organising
 * Analysing
 * Storing & Retrieving
 * Processing
 * Transmitting & Receiving
 * Displaying

Participants
These are the people directly involved in the operation of the system. A good example are the tellers in banks. These are sometimes referred to as direct users.

A participant is someone who enables an information system to exist, either through developing the system, or by providing maintainence. Participants are typically not end users.

Data/Information
This is what the system is required to process and display, among other things. It goes into the system as data, and comes out as useful information.

Information Technology
The information technology is the hardware and software used to process data.

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Hardware is the 'muscle' of the information system, the part that executes all the commands. An example would be a computer processor.

Software
Software is the 'brain' of the information system, the part that gives the commands. A good example would be a spreadsheet program.