I would really love to get more detail about how they structured the full backups and transaction log backups for the database. Are the backups dumped to disk

I would really love to get more detail about how they structured the full backups and transaction log backups for the database. Are the backups dumped to disk before being picked up on tape? Or are the backups streamed directly to the backup system? I'd also would love to know how large is the database that was deleted. Doing a point in time restore of database that's a couple of hundred gigs should be relatively fast (depending on what hardware you are running on).