Much like the Force in Star Wars, Gaffer Tape has a light side and a dark side, and it binds the universe together. Gaffer Tape, not to be confused with Duct Tape, is a heavy cloth pressure sensitive tape. The adhesive is rubber based, which makes it more resistant to heat, and much easier to remove from the surface it has been applied to. And once you see it used on set, you'll be amazed how many applications it's used for! Again, not to be confused with Duct Tape - which is great, in some circles, isn't nearly as awesome as Gaffer Tape!
Gaffer tape is used by all departments, even though it's named for the head electrician. Camera, grip, production, even make-up and wardrobe use gaffer tape! Common uses are to secure cables to prevent tripping or to hide cables from the camera, a quick label maker, to mark focus points or ‘spikes’ noted for talent blocking, holding props or paper, and of course to repair broken things. There are as many colors of gaffer tape as colors in the world, but the most common is matte black, as it tends to not reflect light.