In the domain of SQL Server backup, what is a backup set, backup device, backup media, backup media set, backup media family I'm not a native English speaker and I've read the descriptions in BOL but still can't understand what exactly are they. Can anyone explain in an easy understand way?

Thanks.
The screenshots from SSMS will help you understand the terms:

backup set - is a backup from a single, successful backup operation. E.g. a full database backup created at 8 AM yesterday


You can see that there are 2 backup sets in a single backup media set

backup device - a disk file or tape drive

backup media - tapes or disks where backup are stored
backup media set - in the screenshot - it's the BAK file where backups are added



backup media family - You're creating the 8 AM full database backup and your database is huge, the backup takes more space than 4 tapes can store. Say you have 4 tape devices that are used to backup your database. When one tape is full, you insert a new one. If your database backup takes 20 tapes, that's 5 tapes per each tape device. The 5 tapes created on the tape device 1 belong to the same backup media family, as they have the same "father" - tape device 1