Professional Git

Chapter 2Key Concepts

WHAT'S IN THIS CHAPTER?

• The differences between a centralized and distributed source management system
• The differences between a traditional delta model for tracking source code changes and the way that Git tracks changes
• Why Git is efficient
• How (and why) Git repositories should be organized
• Things to keep in mind when migrating repositories to Git
• Dealing with large files in Git

In this chapter, I'll explain some of the underlying key design concepts that Git uses. Implementation around these concepts forms the basis for how Git works and how to use it. I'll broadly break these concepts down into two categories, user-facing and internal, and show how they differ from more traditional source management systems. Lastly, I'll focus on some important considerations for creating repositories in Git, and managing special content such as binary files.

DESIGN CONCEPTS: USER-FACING

Version control systems (VCS) such as Git can be broadly classified as either centralized or distributed. Git is an example of a distributed version control system (DVCS). Other systems in this category include Mercurial and Bazaar. Examples of a centralized version control system (CVCS) would be Concurrent Versions System (CVS) and Subversion.

The fundamental differences between a DVCS and a CVCS have to do with how the system manages repositories and the workflow that the user employs to get content into the server-side part of the system.

Centralized Model

Figure 2.1 illustrates ...