What is the difference between a factory backup and a recovery disk?

To me a simple question, so I'm hoping for a simple answer.

When I first got my laptop I created a recovery USB using DBR. This is a little over 8gb in size, and is named SYSRECOVERY.

At that time I did not create a factory backup.

Having recently been reading up on things related to restoring a system in the event of hard disk failure etc., I saw that Dell said you should create both a recovery media USB and a factory backup. So I got a new USB and today created a factory backup.

Looking at this, it is also called SYSRECOVERY and both have exactly the same list of files and folders and are almost the same size.

So just what is the difference between these 2 options (if any)?

Or do I now have 2 USBs that will do exactly the same job of restoring my laptop to factory condition?

AndIf there is no difference, why does Dell offer both (and advise you to create both)?

Thank you