Computers are sometimes described as:

(a) Mainframe

(b) Mini

(c) Micro

A Mainframe Computer is one that can undertake many tasks simultaneously and will be linked to many different input and output devices.

A Micro Computer is intended to be used by one operator for one task at a time, and comes bundled with a limited range or Visual Display Unit (VDU). However, modern microcomputers are far more powerful than mainframe computers and if linked together in a network they can form a basis of a sophisticated computer accounting system. Due to invention of increasingly powerful microcomputers the term mini computers has disappeared

Computerized accounting systems fall into 2 broad types.

  1. Centralized systems: Where processing of data takes place in a specialised computer department.
  2. Distributed systems: Where processing of data takes place in the user computer department.

These 2 types are not mutually exclusive. Therefore in centralised systems, data may bepartly processed in the user departments using remote terminals; and in distributed systems, the user department computers may be linked or networked with some of the data being further processed centrally.

In smaller businesses there is often a single micro computer, which is used for all accounting routines and is located within the general accounts office. For audit purposes this is regarded as a distributed system as the computer is operated by accounts personnel rather than specialist computer personnel.