If you don’t want to save changes you made to your document since you opened or
last saved it, you can undo the changes.
Here are ways to undo changes:
To undo your most recent change, choose Edit > Undo.
To undo multiple changes, choose Edit > Undo multiple times. You can undo any
changes you made since opening the document or reverting to the last saved version.
To undo one or more Edit > Undo operations, choose Edit > Redo one or more times.
To undo all changes you made since the last time you saved your document, choose
File > “Revert to Saved,” and then click Revert.