You can create a project snapshot any time by going to project settings following the Snapshots tab. Moreover, the project snapshots are created automatically once you import new strings or perform a search/replace, so you can always revert to the previous version (enable Automatic snapshot on upload).
Users on Essential plans and higher can enable the Automatic daily snapshots option to keep backups accurate.
Restoring from a snapshot is done by creating a project copy from snapshot. All the project settings, contributors, comments, screenshots and statistics are preserved when restoring the project copy from the snapshot.