Complex sentence: Dumbwaiters are small freight elevators that are not intended to carry people or live animals and which, when located in modern structures, including both restaurants and private homes, often connect two floors, usually with one end in a kitchen.
Split into simpler sentences: Dumbwaiters are small freight elevators that are not intended to carry people or live animals. In modern private homes, they often connect two floors, usually with one end in a kitchen.