A hydrogen bomb, also known as a thermonuclear bomb, is a type of nuclear weapon that uses fusion to release a massive amount of energy. It works by combining light atomic nuclei, such as those of hydrogen, under extreme heat and pressure, resulting in a powerful explosion. This process is similar to what powers the sun. Unlike atomic bombs, which rely on fission (splitting heavy atomic nuclei), hydrogen bombs can produce explosions thousands of times more powerful. They typically use a fission bomb as a trigger to initiate the fusion reaction, making them one of the most destructive weapons ever created.