A boomerang is usually thought of as a wooden device cut from a tree trunk, although historically boomerang-like devices have also been made from bones. Modern boomerangs used for sport are often made from carbon fiber-reinforced plastics or other high-tech materials. Boomerangs come in many shapes and sizes depending on their geographic or tribal origins and intended function.
An important distinction should be made between returning boomerangs and non-returning boomerangs. Returning boomerangs actually do fly and are examples of the earliest heavier than air man made flight. A returning boomerang has two or more airfoil wings arranged so that the spinning creates unbalanced aerodynamic forces that curve its path so that it travels in an elliptical path and returns to its point of origin when thrown correctly. While a throwing stick can also be shaped overall like a returning boomerang, it is designed to travel as straight as possible so that it can be aimed and thrown with great force to bring down game. Its surfaces therefore are symmetrical and not uneven like the airfoils which give the returning boomerang its characteristic curved flight.
The most recognizable type of boomerang is the returning boomerang; while non-returning boomerangs, throwing sticks (or shaunies) were used as weapons, returning boomerangs have been used primarily for leisure or recreation. Returning boomerangs were also used as decoy birds of prey, thrown above long grass in order to frighten game birds into flight and into waiting nets. Modern returning boomerangs can be of various shapes or sizes as can be seen in a photo in the Modern use section.
Historical evidence also points to the use of non-returning boomerangs by the ancient Egyptians, Native Americans of California and Arizona, and inhabitants of southern India for killing birds and rabbits. Indeed, some boomerangs were not thrown at all, but were used in hand to hand combat by Indigenous Australians.
Boomerangs can be variously used as hunting weapons, percussive musical instruments, battle clubs, fire-starters, decoys for hunting waterfowl, and as recreational play toys. The smallest boomerang may be less than 10 centimetres (4 in) from tip to tip, and the largest over 180 centimetres (6 ft) in length. Tribal boomerangs may be inscribed and/or painted with designs meaningful to their makers. Most boomerangs seen today, are of the tourist or competition sort, and are almost invariably of the returning type.