One of the most powerful features of Google Apps is revision history. With revision history, you can view all of the changes ever made to a Google Doc, Slide, Sheet, or Drawing. You can also use revision history to restore your file to that exact point in time. With shared files, you can use revision history to see which person made specific edits and also restore any version of the file. No edits are ever lost. Ever. Such a powerful feature.
Step 1: Open up your Google Doc, Google Sheet, Google Slide, or Google Drawing. Then click File > See revision history. You can also click the grey text to the right of “Help” to access revision history.
Step 2: Click on a timestamp on the right to view a previous version of your file. To open up more timestamps click show more detailed revisions. Text that was deleted will be shown with strikethrough. Text that has been added will be highlighted in a different color. Click the arrows to scroll through the list of changes.

Step 3:  If your document was a collaborative document, you will see who edited by matching the color of text to the color next to the user's name.
Step 4: To revert back to a previous version simply click where it says Restore this revision in blue text.
Step 5: If you wish to exit revision history without making any changes, click the white back arrow on the top left of your screen.
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