This article is an introduction to genetic algorithms and their implementation on a computer. Genetic algorithms are based on processes that can be found in natural evolution. Their origin, as mentioned before, lies in Biology rather than Computer Science. The exact mechanisms behind natural evolution aren't known very well, but some of its aspects are. The living being can be 'built' by decoding its chromosomes.
Evolution is a process that works on chromosomes instead of the living beings they represent.
Natural selection is the relation between chromosomes and the performance of their decoded structures. The process of natural selection ensures that chromosomes that represent a good structure will more often reproduce than others. Evolution occurs while reproducing. Mutations can be the reason that chromosomes of children sometimes differ from the ones of their parents in certain places. The chromosomes of the parents are combined in a certain way to create new and different chromosomes for the children.