Fireworks are a class of explosive pyrotechnic devices used for aesthetic, cultural, and religious purposes. A fireworks event (also called a fireworks show or pyrotechnics) is a display of the effects produced by firework devices. Fireworks competitions are also regularly held at a number of places. Fireworks take many forms to produce the four primary effects: noise, light, smoke and floating materials (confetti for example.) They may be designed to burn with flames and sparks of many colours, typically red, orange, yellow, green, blue, purple, silver and gold. Displays are common throughout the world and are the focal point of many cultural and religious celebrations.