Down in the footer you should see something of the format "vX.X.X", which denotes the current version of this website. This page explains how that version number is derived.
Versioning here borrows from the concepts of Semantic Versioning, tweaked to better fit how this website is developed.
The format
Bumped when
Any existing structure changes — the structure of the code, the files, or anything else with a defined structure. Basically, this covers re-writes of the website.
Bumped when
New content is added — text, images, even whole pages. So long as the existing structure is adhered to.
Bumped when
Existing content is modified. This covers things like: