What is Git?

What Git is

Git is an open source version control system that records every change made to a codebase. Any change can be reviewed or undone, and several developers can work on the same project safely.

Linus Torvalds, the creator of Linux, wrote Git in 2005. The Linux kernel team had been using a commercial tool called BitKeeper, and lost free access to it. Torvalds wanted a replacement that was fast, worked without a central server and protected the history from damage.

A few months later he handed day to day maintenance to Junio Hamano, who has led the project since. Git spread beyond Linux as hosting sites such as GitHub appeared from 2008 onward. It is now the standard version control system for software projects of all sizes.

How Git works

Git tracks a folder of files called a repository. When you reach a point worth saving, you choose which changes to include, which is called staging, and then make a commit. A commit is a snapshot of the project with a message, an author and a unique ID. The chain of commits is the project history, and you can go back to any of them.

A branch is a separate line of work. You can create a branch to build a feature or fix a bug without touching the main branch, then merge it back when it is ready. If two people changed the same lines, Git reports a merge conflict and asks you to choose the right version.

Git is distributed, which means every copy of a repository contains the full history. You clone a repository from a remote, such as one hosted on GitHub, work and commit offline, then push your commits to the remote and pull the commits that others made. A pull request is a feature of hosting sites, built on top of Git branches.

Key features of Git

• Complete history

  Every commit records what changed, who changed it and why. You can compare versions or restore an older one at any time.

• Cheap branching

  Creating and switching branches takes almost no time or space. This encourages trying ideas safely and keeping work separate.

• Distributed design

  Each clone is a full copy of the repository. You can commit, view history and branch with no network connection.

• Staging area

  You pick exactly which changes go into the next commit. This keeps commits small and focused.

• Data integrity

  Every commit is identified by a hash of its contents. Damage or tampering in the history is detected.

• Speed

  Most operations run locally and finish almost instantly, even on large projects with long histories.

When to use Git

Git compared with alternatives

How to start learning Git

1. 01Install Git from git-scm.com and run git --version to check it.
2. 02Set your name and email with git config, then run git init in a practice folder.
3. 03Learn the daily loop: git status, git add, git commit and git log.
4. 04Practice creating a branch, merging it and resolving a small merge conflict on purpose.
5. 05Read the free Pro Git book on the official site and push a practice repository to a remote such as GitHub.

What Git costs

Git is free and open source under the GNU General Public License version 2. There are no fees for personal or commercial use. Hosting services that store your repositories online have their own free and paid plans.

How DATAL Projects uses Git

Git is part of our software development work in the Philippines. Common uses:

• Version history for every project
• Branches for new features
• Safe rollbacks

Common questions about Git