There basically 4 different types of homes one come across:

Single Family Homes:  These are the homes where only the Fences are shared with the neighbors.  Typically, these homes come with some decent back yard, side yards and the front yard.  Depending upon how old / new the community is, there could be no monthly HOA or low HOA.

Duets:  Very rare to find. You would find two homes constructed together.  These homes have only one wall sharing.  That means, the other side is always open and so, it makes both the homes corner units.  You would find that both the homes have some back yard, side yard and front yard.   The fences are shared.  Typically the Duets come with monthly HOA.

Town Homes:

You own the space.

Condos:

You don’t own the land.   The land is owned by all the home owners under that association.