git init          
git add .
git add [filename]

git clone ~/folder_A ~/folder_B
git clone git://url
git clone ssh://url

git add files // adds files ready to be commited
git mv prev_place target_place //moves files
git rm files //removes files from working directory but adds it to the staging index
git rm --cached files //stops tracking but keeps files in working directory

git reset --hard

git revert branch

git commit -a --amend //replaces previous commit

git checkout <commit_id>

git fetch //from the original repo that you have forked
git fetch remote
git pull //fetch & merge
git am -3 patch.mbox
git apply patch.diff

git commit -a //adds all changed files & commits all changes
git format-patch origin //create set of diffs
git push remote //push to origin or remote
git tag //mark current version

git status
git diff old_id new_id
git log -p file|dir
git blame file
git show id //meta data & diff
git show id:file
git branch //can list all branches both local and remote
git tag -l //shows list

git checkout branch //switch working dir to branch
git merge branch //merge into current branch
git branch branch_name //branch current
git checkout -b new_branch another_branch //branch new branch from another branch and switch to new branch

git diff [--base]
git diff --ours
git diff --theirs
git log --merge
gitk --merge