Many credit an orthopedist with developing the first working chainsaw in the early 1800's, because his instrument was similar to the 20th century version. However this was a smaller tool used exclusively to cut bone, and no correlation exists between the two.

A chainsaw consists of an engine, a clutch and sprocket, a guide bar and a chain. It can be powered by electricity, compressed air, hydraulics, or, the most common, a two-stroke engine. As with many tools used in industrial and outdoor work, the Occupational Safety and Health Administration (OSHA) requires they be equipped with parts to protect the operator. Mufflers, chain guards, hand guards, and throttle interlocks are examples of OSHA's safety guidelines.

Chainsaws come in a variety of styles, sizes and prices. The smaller models are used by property owners, farmers and gardeners, while the larger ones are used by professional woodsmen, tree surgeons, and even the military.

Although primarily used for tree work, some specialty chainsaws have been developed for other applications. Modified saws are used by wood carving artists, and the construction industry uses specialty ones for cutting concrete, stone and brick. These saws have diamond grit embedded in the teeth of their chains and use water as a lubricant. The construction saws are also used by fire departments to gain entry to buildings and other damaged structures during an emergency situation.

When purchasing a chainsaw, there are two things the prospective buyer must consider: what size saw the job requires and the weight of the saw. Using a saw with more power than is needed, or a saw that is too heavy, can lead to difficulties. A small, lightweight saw will usually be powerful enough for the average consumer. It is also important to buy a chainsaw from a dealer who can service it or find a nearby business that provides this service.

A chainsaw has effective and sharp moving parts. The blade is capable of moving at a speed of 45 miles per hour, depending on the type of power it uses, its size, and the speed at which the operator sets the mechanism. For this reason the operator should be outfitted with protective gear at all times. This should include a hard hat, gloves, ear plugs, safety goggles, special leggings, and steel toe boots.