Git is a distributed version control system designed to track changes in source code throughout the software development lifecycle. Unlike older centralized systems, every developer working with Git holds a complete copy of the repository, including its full history. Git stores data as snapshots of the project at specific moments in time rather than as lists of file changes, which makes operations like branching, merging, and reverting both fast and efficient.
To understand Git, it is essential to grasp its three main areas. The working directory is the ordinary filesystem where files are edited and viewed; it contains the files checked out from the repository at a particular state. The staging area, sometimes called the index, acts as an intermediate buffer where changes are prepared before they become part of the project history. Finally, the repository itself, stored in a hidden .git directory, holds the committed snapshots, branches, tags, and other metadata that make up the project's permanent record.
A commit is the fundamental unit of history in Git. Each commit captures a complete snapshot of every tracked file at the moment it was created, identified by a unique SHA-1 hash that guarantees its identity. Commits also store metadata such as the author, the date, and a human-readable message describing the change. Because commits are content-addressed and immutable, they form a reliable chain of evidence for every modification made to the project.