Compound fireworks are a relatively new concept in the industry. Essentially a compound firework is a group of fireworks that are pre-fused and connected at the manufacturing stage to provide a display pack. A compound firework is usually fixed to a wooden board to stop it flexing and thereby prevent any of the internal fuses from coming apart.
A Compound Firework has one single fuse to light it and once lit will fire all the fireworks. So what you end up with is a pre-configured firework display done for you. Compound fireworks brings display fireworks to the retail market and if you're looking for that WOW firework, then compound is the way to go.