Many services also offer a feature called versioning. This saves incremental changes you make to files as recoverable snapshots of the file. It's useful in case you need to get back information from an earlier version or if your latest file save becomes corrupted. Services vary widely in how many versions they keep and how long they're saved. Best-in-class services, such as SOS Online Backup and SpiderOak ONE keep an unlimited number of file versions forever.
If you want to download as videos itself, you can use other free tools like Free Youtube Download to download all videos with a single click. Please be careful while installing this tool as it optionally installs a browser toolbar and modifies search preferences. So please make sure you read and uncheck the optional checkboxes while installing to avoid surprises in your browser.