Natural Selection:This is the process where organisms better adapted to their environment tend to survive and produce more offspring. It's like being the best player in a video game - you're more likely to 'win' (or survive).
Adaptation:This refers to the changes in physical or behavioral characteristics that have evolved over time by natural selection and make an organism better suited for survival in its environment. It's akin to leveling up your character in a game so they're better equipped for challenges.
Evolutionary Fitness: This term describes how well a species is able to reproduce in its environment compared with other species. If we stick with our video game analogy, it would be like comparing high scores - those with higher scores (greater fitness) have done better at 'playing' the game of survival.