a) Homoannular Diene:- Cyclic diene having conjugated double bonds in same ring.
b) Heteroannular Diene:- Cyclic diene having conjugated double bonds in different rings.
c) Endocyclic double bond:- Double bond present in a ring.
d) Exocyclic double bond: - Double bond in which one of the doubly bonded atoms is a part of a ring system.
Here Ring A has one exocyclic and endocyclic double bond. Ring B has only one endocyclic double bond.