The term "rigger" originated in the days of sailing ships when sailors were responsible for raising and maintaining a complex system of sails and rigging. In modern usage, it generally refers to someone who sets equipment up and prepares it for use. According to the U.S. legal worker definition, a rigger is anyone who attaches or detaches lifting equipment to loads or lifting devices.
There are a number of different categories of riggers working in several industries. In the military, riggers are responsible for maintaining and setting up things like parachutes or airdrop equipment. In the theater industry, riggers manage pieces of a stage set, moving props and changing production scenes. Riggers in the marine industry are involved with setting up the pieces of equipment necessary to keep the ship functioning: ropes, pulleys, winches, cables.
Most commonly, however, jobs are found within heavy construction, often in the oil or mining industry. This type of rigger is also referred to as a Rig Technician. In the oil industry there are several levels of Rig Technicians, ranging from motorhands to derrickhands to drillers, depending on skill level and job duties. Riggers in this industry are responsible for attaching pieces of heavy machinery, connecting the parts together and anchoring pieces to fixed structures with bolts and clamps. They also control and manage all the movement of the machinery while it is operational, and then take it all apart when the job is finished.