Although this sounds like a fancy engineering term, electrical conduit really only indicates a housing that carries wiring safely through a building or area. It keeps the wiring from being damaged by the elements, especially water or moisture buildup. The conduit system is regulated by state and national codes, so you can't just build your own without doing some research.
Installing electrical conduit is a job that takes a lot of experience. The people who install it are specialists, dealing with many types of material throughout their careers. Usually, this housing is constructed of fiber, metal, plastic or clay, all of which are relatively demanding materials. These technicians can adapt a conduit so it can be placed under water and still suffer no harm.
Electrical conduit can be installed inside concrete if it's the right type. This is how businesses can set up displays running on electricity in the middle of a room, with no visible outlets. You can tell electrical conduit styles apart by looking at how thick the tubing is, the material that has been implemented, and the amount of flexibility the conduit allows.
You can get tubing in all styles, from rigid, non-metallic, unthreaded tubing to a flexible conduit made from metal. This last style is pretty to look at, as it is simple a tunnel of ribbed steel that houses the wiring. It will not stay bent, however.
Electrical conduit bending is used when the housing needs to go around curves or corners. It must be done by a skilled technician to ensure that the wiring remains functional and that industry standards are met. This does not need to be done ahead of time, but can be done as needed during the job itself.
Electrical conduit fittings are used when more conduit bending is not helpful or legal. These fittings resemble those used in modifying plumbing pipes, but they are not the same. The strongest fittings are those constructed of cast iron. Most conduit fittings have an opening where you can reach in and work on the wiring inside.
This is a job for skilled professionals. They know how to keep themselves and everyone around them safe. Ask for help when faced with an electrical conduit problem.