Forelimbs of cat, lizard used in walking; forelimbs of whale used in swimming and  forelimbs of bats used in flying are an example of

Forelimbs of cat , lizard  used in walking;  forelimbs of whale used in swimming and  forelimbs of bats used in flying are an example of homologous organs.

Though these forelimbs perform different functions in these animals, they have similar anatomical structure. These structures are described as homologous structures. Homology is the similarity due to common ancestry. However, the adaptation of these structures to different needs is called adaptive radiation (divergent evolution).