Understanding the Differences Between git fetch and git pull

Git is the most widely used distributed version control system, offering features such as collaborative editing, backup, version management, permission control, history tracking, and branch management. However, developers often wonder whether to use git fetch or git pull when updating code.

Related concepts

Working directory: The local folder where you write code, e.g., a study folder on your computer.

Staging area: An intermediate stage before committing to the repository; stored in the hidden .git directory as the index file.

Local repository: The repository that lives on your machine; after git commit the staged changes are saved here.

Remote repository: A repository hosted on a server for collaboration; interaction is done via git push and git pull .

Remote cache: The local copy of the remote repository, updated by git fetch or git pull but not merged until you explicitly do so.

When you commit locally, a commit ID is generated. The .git/refs/head directory stores the commit ID of your local branch, while .git/refs/remotes stores the commit ID of the tracked remote branch.

.git/refs/head/[local-branch]

.git/refs/remotes/[tracked-remote-branch]

git fetch updates the remote cache without changing the local branch. After a fetch, the head commit ID remains the same (e.g., A), while the remote commit ID becomes the latest (e.g., B). You must manually merge the two versions, which may produce conflicts that need resolution, resulting in a new commit (C).

Summary of fetch: It updates the remote reference (the commit ID under remotes ) but does not alter the working files until you merge.

git pull performs a fetch followed by an automatic merge. After a pull, both the local head and the remote reference point to the new commit ID (B), and the updated code appears in your working directory.

Common points & differences

Both git fetch and git pull retrieve updates from the remote server. The key difference is that git fetch only updates the remote cache, while git pull also merges the changes into the local branch.

git fetch commands

git fetch  # fetch remote updates
git diff FETCH_HEAD  # compare remote latest commit with local repository
git merge FETCH_HEAD  # merge after verification

Conclusion

In many scenarios, using git fetch instead of git pull is advisable because git pull creates a merge commit by default, which can complicate history and make debugging harder. However, git pull is convenient for simple workflows, small teams, or when using a centralized VCS approach.