Q: You're halfway through coding a feature when an urgent bug report comes in. You need to switch branches immediately, but your changes aren't ready to commit. How do you save your in-progress work?

Use git stash to save your uncommitted changes onto a stack without committing them:

• git stash saves both staged and unstaged changes to tracked files. Untracked files are not stashed by default — add -u (or --include-untracked) to include them. Add -a to also include ignored files.
• git stash list shows all stashes. They're numbered stash@{0}, stash@{1}, etc.
• git stash pop applies the most recent stash and removes it from the stack. git stash apply applies it but keeps it on the stack — safer if you want to apply the same stash to multiple branches.

Key details: Don't use stash as long-term storage — stashes are easy to forget. If the work will sit for more than a few hours, commit it on a throwaway branch instead.

git stash push -m "WIP: user profile feature"
git switch hotfix/critical-bug
# ... fix the bug, commit, push ...
git switch feature/user-profile
git stash pop

• git stash drop stash@{2} removes a specific stash. git stash clear removes all.
• You can create a branch directly from a stash: git stash branch new-branch stash@{0} — useful if the stash conflicts with current work.