Napalm is a flammable liquid used in warfare, primarily known for its ability to stick to surfaces and cause severe burns. It is a mixture of a gelling agent and a petroleum-based fuel, which creates a sticky, incendiary substance. First developed during World War II, it was used extensively in conflicts such as the Vietnam War. The use of napalm has been controversial due to its devastating effects on both military targets and civilian populations. Its ability to create intense heat and widespread destruction has led to international debates about the ethics of using such weapons in warfare.