There are two main types of AS:
Stub AS: This is an AS that is connected to only one other AS. It is comparable to a cul-de-sac (dead-end street) in our road analogy; usually, only vehicles coming from or going to houses on the street will be found on that street.
Multihomed AS: This is an AS that is connected to two or more other ASes. It is comparable to a through street in our road analogy, because it is possible that cars may enter the street and pass through it without stopping at any of the street’s houses.