The document summarizes key concepts and commands of version control systems using Git. It shows how Git allows creating repositories to track changes to files over time. Developers can add, commit, push and pull changes. Branches allow parallel development while tags help mark important commits. Distributed version control allows multiple replicas of the repository and independent work with a central shared source of truth.

1. Before and After
Without version control system
Day 1 Day 2 Day 3
Project Project Project
Directory Directory Directory
bytes bytes bytes
bytes bytes bytes
bytes
With version control system
Day 1 Day 2 Day 3
Project Project Project
Directory Directory Directory
bytes bytes bytes
bytes bytes bytes
bytes

2. High level structure
Centralized Distributed
Team
Team Lead
Lead
Sr.Dev
Sr.Dev
Central
Repository Sr.Dev Sr.Dev
Jr.Dev
Jr.Dev
Jr.Dev Jr.Dev Jr.Dev Jr.Dev
Jr.Dev Jr.Dev

3. Features

Distributed development.

Every Developer has full copy.

Most operation are local, so its fast.

Strong support for non-linear development.

4. Create repository
Repository created
MyProject
repo
$ git init

5. Clone a repository
Remote
repo
Local
repo
Cloning complete repository to local
$ git clone <url>

6. Adding files/directories (modified)
Working Staging
directory area
stage files
$ git add <file/dir name>

7. Committing changes
Staging Local
Why commit is important : area repo

Each commit gets an SHA1
hash key.

What you put in is what
you get out.
commits
$ git commit -am “<commit message>”

8. Reset changes
Working Staging Local
directory area repo
Add – for modified
Or new files
Remove for staging
area
$ git reset
$ git reset --hard

9. Key points

Git add :
– To add new files.
– To add files to staging area (shortcut: commit -a).

Git reset :
– Clear staging area.
– Clear local changes with “--hard” option.

10. Status of untracked/modified files
Working Staging Local
directory area repo
stage files
commits
$ git status

11. Remote repository
Remote
repo
Local
repo
Copy url name only
$ git remote add <repo_name> <url>

12. Key points

Git clone :
– Creates a new repository by copying everything from an
existing repository.

Git remote add :
– Creates an entry with the name of a particular url in git
config file.

13. Pushing changes
Working Staging Local Remote
directory area repo repo
Push changes
$ git push <repo_name> <branch_name>

14. Pulling changes
Working Staging Local Remote
directory area repo repo
Pull changes
$ git pull <repo_name> <branch_name>

15. Fetching changes
Working Staging Local Remote
directory area repo repo
Fetch changes
Re
ba
se
$ git fetch <repo_name> <branch_name>
$ git rebase <repo_name>/<branch_name>

16. Key points

Git pull :
– Internally it is 'git fetch' + 'git merge'.

Git fetch :
– Gets all the changes but does not apply to working copy.

Git rebase :
– Changes the commit history to match remote repo and applies
changes to working copy.

There are two ways to integrate changes 'merge' and 'rebase'
respectively.

17. Create branch
You are here
B1
Master
$ git branch <branch_name>

18. Switch between branch
B1
Master
B2
You are here
$ git checkout <branch_name>

19. Merge branch
B1
You are here
Master
$ git merge <branch_name>

20. Tagging
Master
Tagged a commit
$ git tag <commit hash key>

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Prathamesh Nevagi