The question is too vague. A "unit" can be defined as anything from a squad of 8 men to a Regiment or even a Division.Very, very broadly speaking and using the British as a template;4 men in a Brick2...
A "unit" can refer to any type of organization. It is used to refer to a division or as small as a company or squad(6 men). This is a term used to refer to the organization of soldiers that you are a...