Git Basics Explained

Git is a distributed version control system that tracks changes in files, enabling collaboration and history management for projects. Here’s a concise guide to learn Git.

Key Concepts

• Repository (Repo):
  A project folder tracked by Git. Contains all files and their history.
• Commit:
  A snapshot of changes at a point in time (with a unique ID and message).
• Branch:
  An independent line of development (default: main or master).
• Remote:
  A cloud-hosted repo (e.g., GitHub, GitLab and even in a local folder) for team collaboration.
• Staging Area:
  A “preview” space where changes are prepared before committing.

Essential Commands

Command	Description
git init	Creates a new repo in the current folder.
git clone <url>	Downloads a remote repo to your machine.
git add <file>	Stages changes for commit.
git add .	Stages all files in the current folder.
git commit -m "Message"	Saves staged changes to history.
git status	Shows unstaged/staged changes.
git log	Displays commit history.

Branching & Merging

• Create branch:

  git checkout -b new-branch-name  # Create and switch to a new branch

• Switch branch:

  git switch branch-name           # Switch to target branch
  git checkout branch-name         # Switch to target branch 

• Merge branches:

  git merge branch-name           # Merge <branch-name> changes into the current branch

• Resolve conflicts:
  Manually edit conflicted files, then git add and git commit.

Syncing with Remotes

Command	Purpose
git remote add origin <url>	Links local repo to a remote.
git push -u origin main	Uploads commits to remote (set upstream).
git pull	Fetches remote changes and merges locally.
git fetch	Downloads remote changes without merging.

Undoing Changes

• Unstage a file:

  git reset HEAD <file>

• Discard unstaged changes:

  git checkout -- <file>

• Revert a commit:

  git revert <commit-id>  # Creates a new commit undoing changes

Best Practices

1. Commit often: Small, logical changes with clear messages.
2. Branch early: Use branches for features/fixes.
3. Pull before push: Avoid merge conflicts.
4. Use .gitignore: Exclude files (e.g., logs, binaries).
5. Review changes:

   git diff          # Unstaged changes
   git diff --staged # Staged changes

Example Workflow

# Clone a repo
git clone https://github.com/user/project.git

# Create a new branch <dev> adn switch into it
git checkout -b dev

# Make changes, then stage & commit
git add index.html
git commit -m "Up date index"

# Push to remote branch
# (Create a new remote branch if there's no dev branch in remote repo.)
git push origin dev:dev

Git’s power lies in its flexibility—start with these basics, then explore advanced features as needed!