Those are eggs. Clear ones are possibly viable white ones are bad ones.
You may be able to see tiny eyes forming in them, and then the tails will pop out and then their will be "wigglers" tiny baby fish like they are stuck there wiggling. After that free swimming tiny babies. Which at any point these may be eaten by the parents or other fish.
Generally an Angelfish will be chasing off any thing coming near. They get tired though and sleep and sometimes a sneaky fish will eat them.
I have tried leaving a night light on for the parent fish so they can see the fish coming to eat them and chase off the other fish.
Angels will pic at a spot to clean it up to lay eggs.