Final answer:
An adaptation is a heritable trait that aids in an organism's survival. It evolves through natural selection, and examples include webbed feet and thick fur. In contrast, an exaptation is a feature that arose for a different purpose but has since acquired a new function, like bird feathers.
Step-by-step explanation:
An adaptation is a heritable trait or behavior in an organism that aids in its survival and reproduction in its present environment. It is a 'match' of the organism with its environment, and it evolves through natural selection. For example, the webbed feet of a platypus are an adaptation for swimming, and the thick fur of a snow leopard is an adaptation for living in the cold.
On the other hand, an exaptation is a feature that arose for a different purpose but has been co-opted for a new function. It is not directly related to the organism's survival in its present environment. An exaptation can provide a selective advantage by providing a new function that helps the organism in its current environment. A classic example is bird feathers, which originally evolved for temperature regulation and later became important for flight.