What is the purpose of adding a version in CSS? [duplicate]

Question

I´m using Gridless Boilerplate and this is how the main.css file is called in the header:

<link rel="stylesheet" href="assets/css/main.css?version=1" />

I'd like to know what the purpose of adding "?version1" is.

Answer 1

It's used to avoid caching issues. When you edit your css file you'll increment that version number and the browser will (presumably) fetch a new copy rather than using its cached version.

See Cache-Busting via params.