Answer:
Homologous structures define similarly structured body parts among organisms that serve different functions. They show common ancestry; an example would be a human arm and horse leg (both made of bone, but different uses).
Analogous structures define differently structured body parts that serve the same function. They do NOT show common ancestry. An example would be a whale fin & dolphin fin; one is made of bone and the other cartilage, but they are both used to swim).