Final answer:
Git uses a two-stage system for saving files that involve a staging area where changes are prepared, and a repository where changes are permanently recorded after a commit.
Step-by-step explanation:
The two-stage system that Git uses to save files involves two main areas: the staging area and the repository. Initially, changes made to files are worked on in the working directory. Once you are ready to mark a version of a file(s) to go into your next commit, you stage the changes, which means they are added to the staging area. The staging area is effectively a draft space where Git tracks changes which are not yet recorded in the repository.
After you have finalized the changes in the staging area, you then commit them to the repository. This commit takes a snapshot of these changes and saves it to the repository, creating a commit object that contains a unique identifier along with other metadata, including a message describing the changes, which allows you to keep a history of all changes made over time. As you continue to work, you can repeat this two-stage process—selectively staging changes and then committing them— to efficiently manage and record the evolution of your project.