What do the numbers in a version typically represent (i.e. v1.9.0.1)?

version

Solution

In version 1.9.0.1:

1: Major revision (new UI, lots of new features, conceptual change, etc.)

9: Minor revision (maybe a change to a search box, 1 feature added, collection of bug fixes)

0: Bug fix release

1: Build number (if used)—that's why you see the .NET framework using something like 2.0.4.2709

You won't find a lot of apps going down to four levels, 3 is usually sufficient.

Problem

I've always assumed each number delineated by a period represented a single component of the software. If that's true, do they ever represent something different? How should a version number be structured to start assigning versions to the different `builds` of my software? As an aside, my software has five distinct components.

Original source

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