The management of changes to documents, computer programs, web sites, and other collections of information. Changes are usually identified by a number or letter code. For example, an initial set of files is “version 1”. When the first change is made, the resulting set is “version 2”, and so on. Versions can be compared, restored, and with some types of files, merged.
Also known as revision control and source control.
Side note: A version should never be called “Final,” because invariably it will change, and then you have hilariously awkward versions like “Final 2,” “Final 3,” etc.