Simple alicyclic compounds are the cycloalkanes cyclopropane, cyclobutane and cyclohexane. A polycyclic cycloalkane is Decalin. Bicyclic alkanes are norbornene and norbornadiene. Spiro compounds have bicyclic connected through one carbon atom.
The mode of ring-closing in the formation of many alicyclic compounds can be predicted by Baldwin's rules.
An exocyclic group is always placed outside the ring structure, take for instance the exocyclic double bond on the left:
See for an example isotoluene.
The placement of double bonds in many alicyclic compounds can be predicted with Bredt's Rule.