Jelly fish come under PHYLUM COELENTERATE.
Characteristics of PHYLUM COELENTERATE are:
They live in water.They has a sac like body cavity with a single opening to the outside for ingestion and egestion.They are diploblastic.
Star fish come under PHYLUM ECHINODERMATA
Characteristics of PHYLUM ECHINODERMATA:
They are free living marine animal.They are triploblastic.They have calcium carbonate structures that they use as askeleton.