Difference between full and level 0 rman backups?

Question

Suppose we take a full backup, and after that we take a level 0 backup, both using RMAN and Oracle 10g.

I'm confused in the use of the level 0 backup and full backup. I found that the difference between both is only that level 0 backup is used for incremental backups but full backup isn't.

What are benefits of that full backup which we have take before the level 0 backup? How will Oracle use the full backup and the incremental backup?

When we perform recovery, will Oracle use that full backup which was taken before the level 0 backup?

Answer 1

The RMAN backup concepts guide (link for 11gR2, but the concept hasn't changed):

The only difference between a level 0 incremental backup and a full backup is that a full backup is never included in an incremental strategy.

Full and level zero backups copy all blocks that have data (and more if you're doing image copies), so they are both "full" in that sense.
But if you want to do cumulative or differential backups, the starting point for those must be a level zero incremental backup.