git add [target]

• Target is a list of files
• The files specified by target will become staged
• Any changes made to staged files will be part of the next commit

git commit

• Make a commit
• A commit is a list of changes made to your code since the preceding commit
• Commits all point to the commit that precedes them, called the "parent"
• These parent relationships form a chain of changes, called the "ancestors" of that commit

Branches

• A branch is a label that you can add to a commit

HEAD

• HEAD is a branch (label) on whichever commit is currently checked out
• When your HEAD points to a branch, that branch is moved to any new commits you make
• When your HEAD points to a commit instead of a branch, it is "detached" and no branches are moved

[target]^ and [target]~[n]

• Refer to the parent or nth ancestor of target

git checkout [target]

• Move HEAD to the version of the code at the target
• Target can be a commit hash or a branch name
• If target is a commit hash, then HEAD will point to the commit instead of a branch
• To load your code, git applies all the changes in the ancestor chain, from the first to HEAD, in order

git checkout -b [target]

• Create and checkout a new branch named target
• Target will point to the commit you where on when you ran this command

git merge [target]

• Merging creates a new commit on the branch you are currently on
• This merge commit has two parents: the commit you were on when calling merge and target
• This means that when you load this commit, git will apply all the changes from both ancestor chains
• If target is an ancestor of the current commit, then the merge will just move the branch to the new commit

git rebase [target]

• Change the parent of the current commit to target
• If the current commit is an ancestor of target, then the merge will just move the branch to the current commit

git reset [target]

• Move the branch at HEAD to target
• Can be used to "undo" a commit by making target HEAD^

git revert [target]

• Create a commit that undoes all the changes from target
• If this commit comes after target, the commit undoes all those changes
• You can revert any commit at any point, even if target isn't an ancestor of the current commit

other materials

• https://wizardzines.com/git-cheat-sheet.pdf
• https://wizardzines.com/images/uploads/inside-git.png