Commit

In Git, a commit is a snapshot of your project's files at a point in time. Commits are the building blocks of your project's history. When you make changes to your project, you can group them into a commit. Such a commit represents a set of changes that you want to save—this could be changes to existing files, new files, or deletions of files. Besides the changes themselves, a commit usually includes a commit message, which is a brief description written by the developer to explain what was changed and why.

A chronological chain of commits forms a timeline of your project's development. It is helpful for understanding how the project evolved over time, who made changes, and why. You can reconstruct the state of your project at any point in time by checking out a specific commit—for example, by using git switch.

Each commit is associated with a unique ID, called a hash (e.g. 346ca091076783c70623aba03fb7139d3d27134f, which in most cases can also be shortened as 346ca09 by taking just the first 7 characters of the long hash). This hash acts like a fingerprint for that specific set of changes. Apart from distinguishing commits from one another, you can pass these hashes to various Git commands to refer to specific commits. For example, git diff 346ca09 will show you the changes introduced in that commit.