A commit () is a set of related changes made to Items — that is, Models, Files, and Tags — within a single database save operation. This includes anything from saving item versions, changing the assigned tags of items, or deleting items, to creating a new branch, merging into a branch, and reverting a commit. The changes are saved to the database as a “unit” and, as such, can also be reverted as a unit.

Given a particular commit, you can browse and search the versions of items that were the latest versions at the time of that commit. A schematic representation of this is shown in Figure 2-2: In the first commit, a first version of a model A and a model B were saved. In the second commit, a second version of model A was saved, a first version of a tag T was saved, and model B was tagged by T. In the third commit, model A was deleted and a second version of model B was saved. The database can be browsed and searched with respect to each of the three commits, with each big circle surrounding what you will find.