The island itself represents society, and the fact that it is deserted allows the boys to make it into whatever type of "society" they want. The island has two sides to it, one that faces the ocean, and one that faces the lagoon. The ocean side is rocky with no vegetation and is set apart from the rest of the island. This comes to represent evil, as it is the location where Jack, as the uncivilized leader, gathers with the other boys. It's also the place where Simon and Piggy die. This bare, rocky side of the island is the uncivilized part of society. The lagoon side is protected from the harsh reality and brute force of the ocean. It represents good, as this is where the children swim and play. This is also where Ralph first holds the meetings with the other boys and where they are rescued. This side represents civilization and order in society. Golding, the author, uses the setting of the island as symbols of the good and evil that exist in people and society.
The setting is a deserted island where the boys crash as they are being airlifted to "safety" during WWII. Obviously they never made it to their destination, and unfortunately, none of the adults on board survive.
This affects the boys in that at first the older boys attempt to settle down into a routine as close as possible to the civilization to which they are accustomed. As time goes by, however, they become less and less civilized and more barbaric. This is evident in their complete uniforms at first and then the lack of clothing, the hunting exercises and ceremony of wild boar on the island which includes the painting of their faces, and ultimately, the murder of their own. Of course, this attention to the "dark side" of humanity is the point Golding is trying to make. War, survival of the fittest, lack of proper supervision/rules will lead mankind back to its barbaric and caveman-like roots.