Answer:
Homologous structures are those that share evolutionary and developmental origins. When discussing them one usually refers to those that have different uses in organisms. For instance the malleous and stapes bones in the middle ear of mammals are used to transfer sound whereas in most lizards these bonse are used in jaw articulation.
Other examples will be the forelimbs of a quadrupeds that includes the same bones as the human arm.
Another interesting example is the equivalent of one of the wrist bones in most mammals is used as a pseudo thumb in pandas.
