In Git terms, a "checkout" is the act of switching between different versions of a target entity. The git checkout command operates upon three distinct entities: files, commits, and branches. ... In the Undoing Changes topic, we saw how git checkout can be used to view old commits.

What is checkout and checkin in git?

checkout is getting changes out from the local or remote repository (into your local working directory). checkin is putting changes back into the the local or remote repository (from your local working directory).

What does git checkout -- file do?

The git checkout command can be used in a commit, or file level scope. A file level checkout will change the file's contents to those of the specific commit. A revert is an operation that takes a specified commit and creates a new commit which inverses the specified commit.