What is a version?

A version is an iteration, something that is different than before.

When programmers develop software a version is typically a minor software update, something that addresses issues in the the original release but does not contain enough to warrant a major release of the software.

In the engineering world we like to keep previous copies of our designs so that we can go revert back to them in case something goes wrong. Data corruption, customer changes their mind, or the new idea does not work are some of the reasons we like to keep a legacy around. Having previous copies means that we can see what we did, when we did it, and hopefully why we did it. With versions the what, who, when, why isn’t always so obvious.

What is a revision?

A revision is a controlled version. Webster’s dictionary describes a “revision” as the act of revising, which is to make a new, amended, improved, or up-to-date version.

Back to the software analogy, a revision is seen as a major release of the software. Something that introduces new features and functionality, as well as fixing bugs. In the engineering world we use revisions to document the changes so that anyone can understand what was changed

Revisions will typically happen after some type of approval. The original document is approved meaning that we need to make a revision as we will seek approval to release the changed document. Versions occur during one lifecycle state, revisions are caused by the change of lifecycle.  

Versions are usually temporary, revisions are permanent. What I mean by this is that during the design phase I will quickly build up versions of the design, however 5-years from now I will only care about one version, the one that was released.

In Conclusion

I hope this helps explain the difference or helps you explain the difference to someone else. The easiest thing to remember is that a revision is controlled version, a historical record or a change in design.