Ralph attempts to create a civilization and maintain a set of rules. He envisions a utopia built on democracy, where each boy has a voice and is heard. Also, he imagines a place where everyone has a role to contribute to the welfare of the group.
The signal fire started by Ralph and Piggy is contained to a small point off the coast. Diplomatically, they established shifts for the boys to keep watch of it and make sure it stays lit.
The conch shell is used to call the boys together. Whoever possesses the conch shell is the only one allowed to speak.
CHAOS
Jack undermines the democracy Ralph wants to create, and becomes a dictator who rules through fear. He only values being a hunter and continuously watches as boys are killed by members of his clan.
Jack uses the fire for his own purposes. Near the end, he burns half the forest in hopes to smoke Ralph out. His flames become a chaotic and destructive force used for evil.
The "Monster" is the embodiment of chaos; the severed boar's head is its incarnation. As the novel progresses, we learn the only real monster is the one inside humanity.