These 3 commands that can change/rollback/revert/update a file in your git repository. Whatever you call it.

This post note their differences and their usage.

Firstly, the usage is usually

git checkout/revert/reset myfile

Checkout

• Use this to checkout a branch or specific commit
• This will rollback any changes you have in your working copy
• This will NOT make any changes to the history

Revert

• Use this to rollback changes you have committed
• This adds a NEW commit, hence changes the history

Reset

• Use this to rollback changes made to the index (eg from git add), which will NOT change the history
• Use this to change what commit a head is pointing to, which will change the history

Or you may read this and this on StackOverflow.