Version Control with Git, 2nd Edition

Chapter 4. Basic Git Concepts

Basic Concepts

The previous chapter presented a typical application of Git—and probably sparked a good number of questions. Does Git store the entire file at every commit? What’s the purpose of the .git directory? Why does a commit ID resemble gibberish? Should I take note of it?

If you’ve used another VCS, such as SVN or CVS, the commands in the last chapter likely seemed familiar. Indeed, Git serves the same function and provides all the operations you expect from a modern VCS. However, Git differs in some fundamental and surprising ways.

In this chapter, we explore why and how Git differs by examining the key components of its architecture and some important concepts. Here we focus on the basics and demonstrate how to interact with one repository; Chapter 12 explains how to work with many, interconnected repositories. Keeping track of multiple repositories may seem like a daunting prospect, but the fundamentals you learn in this chapter apply just the same.

Repositories

A Git repository is simply a database containing all the information needed to retain and manage the revisions and history of a project. In Git, as with most version control systems, a repository retains a complete copy of the entire project throughout its lifetime. However, unlike most other VCSs, the Git repository not only provides a complete working copy of all the files in the repository, but also a copy of the repository itself with which to work.

Git maintains a set of configuration ...