Banana is a parthenocarpic fruit whereas oranges show polyembryony. How are they different from each other with respect to seeds?

Banana — Parthenocarpy
Bananas are seedless fruits, and such fruits are called parthenocarpic — meaning the fruit develops without fertilization.
In banana, the ovary develops into the fruit without fertilization taking place at all, so no seeds are formed.
Since parthenocarpic fruits develop without fertilization, they don’t require pollination either.
The banana plant is instead propagated vegetatively (from suckers/rhizomes), not through seeds.

Orange — Polyembryony
The seeds of oranges have many embryos of different sizes and shapes — a phenomenon called polyembryony.
In oranges, additional embryos develop directly from diploid cells other than the egg, such as the nucellus and integument (rather than only from the fertilized egg).