Basic Git and GitHub Interview Questions

If you are just starting out, these are the fundamental Git and GitHub interview questions you must know.

1. What is Git?

Git is a distributed version control system designed to track changes in source code during software development. It allows multiple developers to work on the same project simultaneously without overwriting each other’s work.

2. What is GitHub?

GitHub is a cloud-based platform that hosts Git repositories. Beyond hosting, it supports collaboration through features like issue tracking, project management, and CI/CD (Continuous Integration/Continuous Deployment) pipelines.

3. What is the difference between Git and GitHub?

This is one of the most common Git and GitHub interview questions.

• Git: The actual version control tool that runs locally on your machine.
• GitHub: The hosting service on the web where your Git repositories are stored and shared.

4. What is a Repository (Repo)?

A Repository is a storage space where your project’s files and their entire revision history are saved. It can be local (on your computer) or remote (on a server like GitHub).

5. What are the most common Git commands?

You should be comfortable explaining these standard commands:

• git init: Initialize a new repository.
• git clone: Copy an existing repository to your local machine.
• git add: Stage changes for the next commit.
• git commit: Save your staged changes to the history.
• git push: Upload your local commits to the remote repository.
• git pull: Fetch changes from the remote and merge them into your local branch.
• git status: Check the current state of your working directory.
• git log: View the commit history.

6. What is a Commit?

A Commit is essentially a snapshot of your changes at a specific point in time. Each commit has a unique ID (a hash) and a commit message describing what was changed.

7. What is a Branch?

A Branch represents a separate line of development. It allows you to work on features or fixes in isolation without affecting the main codebase. The default branch is usually called main or master.

8. What is Merging?

Merging is the process of taking the changes from one branch (e.g., a feature branch) and combining them into another branch (e.g., the main branch).

9. What is a Pull Request (PR)?

A Pull Request (PR) is a GitHub-specific feature. It lets you propose changes, request code reviews from teammates, and discuss the code before merging it into the main branch.

10. What is Forking?

Forking is creating a personal copy of someone else’s repository. This allows you to freely experiment and make changes independently without affecting the original project.

11. What is .gitignore?

The .gitignore file tells Git which files or directories to ignore. This is crucial for excluding files like build logs, temporary files, and sensitive environment variables (.env) from your repository.

12. What is the Staging Area?

The Staging Area is an intermediate space where changes are held before they are committed. It allows you to review what will be part of your next snapshot.

13. What is the difference between Merge and Rebase?

Understanding this distinction is vital for answering intermediate Git and GitHub interview questions.

• Merge: Keeps all history and creates a “merge commit.” It is non-destructive.
• Rebase: Rewrites history to make it linear. It moves your entire branch to begin on the tip of the master branch.

14. What is a Git Workflow?

A Git Workflow is a recipe or recommendation for how to use Git to accomplish work in a consistent and productive manner. Examples include Git Flow and GitHub Flow, which define rules for branch management and releases.

15. How do you resolve merge conflicts?

To resolve a conflict, you must manually edit the conflicted files to select the correct code, mark them as resolved, and then commit the changes.

Advanced Git and GitHub Interview Questions

For senior roles, interviewers will dig deeper. Here are the advanced Git and GitHub interview questions to help you stand out.

16. What is a Tag in Git?

A Tag is a reference that points to a specific point in Git history. Tags are typically used to mark release points (e.g., v1.0, v2.0).

17. What is the difference between Soft, Mixed, and Hard Reset?

• git reset –soft: Moves the HEAD pointer but keeps your changes staged.
• git reset –mixed (Default): Moves the HEAD pointer and unstages your changes (keeps them in the working directory).
• git reset –hard: Moves the HEAD pointer and completely deletes all changes.

18. What is Git Revert?

Unlike reset, Git Revert creates a new commit that undoes the changes of a previous commit. This is the safe way to undo changes in a public history without erasing it.

19. What is Cherry Pick?

Cherry Pick is a powerful command that allows you to apply a specific commit from one branch into another, without merging the entire branch.

20. What is Git Stash?

Git Stash temporarily shelves (saves) your uncommitted changes (both staged and unstaged) so you can switch branches to work on something else, and then re-apply them later.

21. What is HEAD in Git?

HEAD is a pointer to the current branch reference. It effectively points to the latest commit in your currently checked-out working directory.

22. What is the difference between ‘origin’ and ‘upstream’?

• origin: The default remote repository you cloned from (your fork).
• upstream: The original repository you forked from. This is used to sync your fork with the original project.

23. What is a Fast-forward Merge?

A Fast-forward Merge happens when there is no divergence between the branches. Git simply moves the branch pointer forward to the latest commit. No new “merge commit” is created.

24. Git Fetch vs Git Pull: What is the difference?

• Git Fetch: Downloads changes from the remote repo but does not integrate them into your working files.
• Git Pull: Performs a git fetch followed immediately by a git merge. It updates your current HEAD with the latest changes.

25. How do you undo the last commit?

If you made a mistake in your last commit, you can use:

• git reset –soft HEAD~1: Keeps your changes staged so you can edit and commit again.
• git reset –hard HEAD~1: Discards the changes completely (use with caution!).