Natural selection is a key mechanism in the process of evolution. It occurs when certain traits or characteristics of individuals within a population provide a reproductive advantage, allowing those individuals to survive and pass on their genes to the next generation. Over time, this leads to changes in the frequency of these advantageous traits within the population, ultimately shaping the species as a whole. Evolution, on the other hand, refers to the change in heritable traits of a population over successive generations. Natural selection is one of the main drivers of this process, as it acts on the genetic variation present in a population, leading to the adaptation of species to their environments.