Borescopes are commonly used in the visual inspection of aircraft engines, aero derivative industrial gas turbines, steam turbines, diesel engines and automotive/truck engines. Gas and steam turbines require particular attention because of safety and maintenance requirements.

Borescope inspection of engines can be used to prevent unnecessary maintenance, which can become extremely costly for large turbines. They are also used in manufacturing of machined or cast parts to inspect critical interior surfaces for burrs, surface finish or complete through holes. Forensic applications in law enforcement and building inspection are also common uses for borescopes.

Rigid borescopes generally provide a superior image at lower cost compared to a flexible borescope, but have the limitation that access to what is to be viewed is a straight line. A flexible borescope can be used to access cavities which are around a bend, such as a combustion chamber or "Burner Cans" in order to view the condition of the compressed air inlets, turbine blades and seals without disassembling the engine.

Fiberscopes are flexible and consist of a fiber optic bundle with an eyepiece at one end, and a lens at the other. The lens is often a wide-angle lens, and the eyepiece is occasionally instead connected to a camera. Some fiberscopes use an additional fiber to carry light from an external source to illuminate the material being inspected, for clearer viewing.

All fiberscopes introduce a certain amount of image distortion; much of this is similar to the distortion of modern night vision equipment. Fiberscope is always flexible and can be very long, say 300ft. Borescope may be rigid or flexible, usually of a reasonable, handy length, say about 36 inches. Always use the right tools for your inspection situations.