Extra details on specific platforms can be found on the related pages, PC, PS3, and Xbox 360.
You can find out about your version in the lower left corner of the 'System' screen (Esc on PC, Start then selecting 'System' on console).
Upgrading Skyrim to the latest patch is usually recommended, as many bugs and glitches are often fixed by the patches. For the patches for the upgraded special edition, see Special Edition Patch. This article is about the patches for the standard game.