What command can be used to undo changes in Git?

In Git, there are several commands to undo changes depending on the situation:

• git checkout -- <file> — undo changes in the working directory for a specific file, reverting it to the last commit state.
• git reset HEAD <file> — remove the file from the index (staging area), but keep the changes in the working directory.
• git reset --hard — revert all changes in the working directory and index to the last commit (all unsaved changes will be lost).
• git revert <commit> — create a new commit that undoes the changes of the specified commit.

Example of undoing all local changes:

git reset --hard

Be cautious with this command, as it permanently deletes unsaved changes.