The fire is a very important symbol throughout the novel, and plays a significant role in the plot. We first see the fire when Ralph states that they need a signal fire to get off the island. In this situation , fire is a technology that the boys can use to get off the island. However, like any technology, readers can also observe how when used wrong the technology can be destructive. Almost immediately after the first fire is built, the negligence from the boys causes it to get out of control, and it can be speculated that the littlun with the birthmark died as a result.
Furthermore, fire in the novel is also seen a symbol of power. It cooks the pig meat that Jack and his hunters collect, it is something that the boys want when they don't have it, and it is used to flush Ralph out of the forest so he can be killed. Readers are constantly reminded in the novel that whoever has the fire has the power.