What Is a Version Number and Why Is It Used?

Definition of Version Number, How They're Structured, & Why They're Important

Screenshot of a Windows10 About Windows Dialog Box
Windows 10 Version Number.

A version number is a unique number or set of numbers assigned to a specific release of a software program, file, firmware, device driver, or even hardware.

Typically, as updates and entirely new editions of a program or driver are released, the version number will increase.

This means that you can usually compare the version number of the software installed on your computer with the version number being released to see if you already have the latest version installed.

Structure of Version Numbers

Version numbers are usually divided into sets of numbers, separated by decimal points.

Usually, a change in the leftmost number indicates a major change in the software or driver. Changes in the rightmost number typically indicate a minor change. Changes in other numbers represent varying degrees of changes.

For example, you may have a program installed that reports itself as version 3.2.34. The next release of the program may be version 3.2.87 which would suggest that several iterations were tested internally and now a slightly improved version of the program is available.

A future release of 3.4.2 would suggest that more substantial updates are included. Version 4.0.2 might be a major new release.

There is no official way of versioning software but most developers follow these general rules.

Version Numbers vs Version Names

Sometimes the word version is used generally to refer to either a version name or a version number, depending on the context.

Some examples of version names include "7" as in Windows 7 and "10" as in Windows 10.

The version number of the initial release of Windows 7 was 6.1 and for Windows 10 it was 6.4.

See my Windows Version Numbers list for more on the real version numbers behind Microsoft Windows releases.

Importance of Version Numbers

Version numbers, as I mentioned in the introduction at the top of the page, are clear indications of what level a particular "thing" is at, most commonly software and other important areas of the operating system.

Here are some pieces I've written that deal specifically with finding the version number that a particular program is at:

Version numbers help prevent confusion about software being updated or not, a very valuable thing in a world of continuous security threats followed quickly by patches to fix those vulnerabilities.