An algorithm is best described as a set of step-by-step instructions to resolve a problem. Each set of instruction is organised in an orderly manner according to how the plan is to be carried out.

Algorithms are often used as a starting point for creating a computer program. Computers are only as good as the algorithm they have been given. Therefore, a lot of planning goes into writing an algorithm because the computer will do what we want it to do and exactly how we want it to be done.

An algorithm must have a starting point, a clear set of instructions, variables, messages and a finishing point. In Computer Science, it is often written abstractly, utilizing variables in place of specific numbers (as per image below).

Algorithms can be used for many different things including calculations, data processing and automation.