Below is the simplest and cleanest breakdown of all key Git concepts used daily by DevOps, SRE, and software engineers, including real-world examples, use-cases, and interview-ready answers.

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1️⃣ What is Git?

Interview Answer:
Git is a distributed version control system (DVCS) used to track code changes, collaborate with teams, manage versions and branches, and ensure rollback capability.

Key Points:

• Distributed → every developer has full repository copy

• Supports branching, merging, rollback, auditing

• Provides collaboration between developers + CI/CD pipelines

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2️⃣ How do you initialize a Git repository?

Command:

git init

What happens?

• Creates a .git directory in the project folder

• This folder stores:

  • commits

  • branches

  • logs

  • configuration

  • hooks (pre-commit, pre-push etc.)

Interview Answer example:
“When we run git init, Git creates a .git directory that stores all metadata needed for version control — such as commit history, branches, configuration, and hooks.”

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3️⃣ What does “git status” do?

Shows:

• untracked files

• modified files

• staged files

• current branch

Command:

git status

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4️⃣ How do you track files in Git?

Using the git add command.

git add filename
git add .     # add all files

Purpose:
Stages the changes so Git starts tracking them.

Interview Answer:
"git add moves changes to the staging area so Git knows which files should be included in the next commit."

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5️⃣ Why do we use commits?

Commit = snapshot + message

git commit -m "Added addition function"

Why required?

• Provides history

• Enables rollback

• Helps to track “who changed what & why”

• Crucial for CI/CD pipelines

Interview Answer:
“Commits help maintain proper version history. Each commit contains an author, timestamp, and commit message, making debugging and rollback easier.”

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6️⃣ View commit history

git log

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7️⃣ Pushing Code to Remote

git push

If remote not configured:

git remote add origin <repo-url>
git push -u origin main

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8️⃣ What is Git Clone?

Interview Answer:
"git clone is used to download or copy an existing remote repository into your local machine."

Command:

git clone <repo-url>

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9️⃣ Difference: Git Clone vs Git Fork

Interview Answer:
“Clone downloads a repo as-is, while fork creates an independent copy under your GitHub account — often used in open-source contributions.”

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🔟 HTTPS vs SSH in Git

HTTPS

• Uses username + password

• Easy to start, but asks credentials repeatedly

SSH

• Uses public/private keys

• Best for DevOps teams

• More secure

Generate SSH key:

ssh-keygen -t rsa

Copy public key:

cat ~/.ssh/id_rsa.pub

Add it to GitHub → Settings → SSH Keys

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1️⃣1️⃣ Branching (Real-World DevOps Example)

Why use branches?

To avoid breaking the production code.

Real Example:
Amazon developers create a separate branch for “Carpenter Service Feature” instead of changing main directly.

Create a new branch

git branch feature-division

Create & switch (most used)

git checkout -b division

Switch branches

git checkout main

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1️⃣2️⃣ Merge, Rebase, Cherry-Pick

These are important interview topics.

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A) git merge

Used to combine two branches.

git checkout main
git merge division

Pros:

• Safe

• Maintains commit history

• Best for team collaboration

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B) git rebase

Moves branch commits to top of another branch (linear history).

git checkout division
git rebase main

Pros:
Clean history
Cons:
Can cause conflicts
Don’t rebase shared branches

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C) git cherry-pick

Pick specific commit(s) from another branch.

git cherry-pick <commit-id>

Use Case Example:
Production bug fix committed in feature branch → pick only that commit to main.

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1️⃣3️⃣ git diff

Shows changes line-by-line.

git diff

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1️⃣4️⃣ Rollback Commands

Undo unstaged changes

git checkout -- filename

Undo staged changes

git reset filename

Rollback a commit (safe)

git revert <commit-id>

Dangerous (history rewrite)

git reset --hard <commit-id>

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1️⃣5️⃣ Git Stash

Used daily by DevOps.

Saves uncommitted work temporarily:

git stash

Restore:

git stash pop

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1️⃣6️⃣ Git Hooks (Real DevOps Example)

Located in .git/hooks

Examples:

• pre-commit → prevent secrets/credentials from being committed

• pre-push → run tests before pushing

• post-merge → notify CI/CD

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Summary: Daily Git Workflow

git pull
git checkout -b feature-x
git add .
git commit -m "Added feature"
git push
Create Pull Request → Merge to main