Some organisms that share a common ancestor have features that have different functions, but similar structures. these are known as

Some organisms that share a common ancestor have features that have different functions, but similar structures. these are known as homologous structures.
Homologous structures are organs or skeletal elements of animals which are connected via a common ancestor. These structures do not have to look exactly the same or have the same function, but they are structurally similar. The example of homologous structures is the forelimbs of vertebrates. In this example, we see that the wings of bats, the arms of primates, the front flippers of whales and the forelegs of dogs and horses are all derived from the same ancestral tetrapod structure.