Without autosave, you’ll lose all work done after the last time you saved whenever SolidWorks (inevitably) crashes. With this option enabled, SolidWorks will save a backup copy of all your unsaved documents every few minutes.
Go to [Settings → System Options → Backup/Recover], enable “Save auto recover information every:” and specify how often you want SolidWorks to save a version of your files.
Now, after SolidWorks crashes, you can click the “Open All” button to recover files when you reopen the program.