Final answer:
Natural selection is a process by which advantageous traits become more common in a population, leading individuals with those traits to have more offspring. Evolution is the broader term for the change in the genetic makeup and traits of a population over time, driven by mechanisms like natural selection, mutation, and gene flow.
Step-by-step explanation:
The main difference between natural selection and evolution is that natural selection is a mechanism by which evolution occurs. Natural selection explains how certain traits become more common within a population because individuals with these advantageous traits are more likely to survive and reproduce. These beneficial traits are then passed down to offspring. Over time, as these traits become more prevalent, the population as a whole changes, and this process is known as evolution. While natural selection works on the variability within a population to select for traits that confer an advantage, evolution is the broader process that encompasses all changes in the genetic makeup and traits of a population over generations, including those produced by natural selection, mutation, gene flow, and genetic drift.