An elevator is a vertical transport vehicle that moves people and goods between floors of a building using electric motors and cables, chains, or hydraulic systems. There are two main types - roped elevators which use cables and counterweights, and hydraulic elevators which use a hydraulic system. Elevators have various components like a car, shaft, doors, and motor. They are used to transport passengers, freight, vehicles, and aircraft and have additional features like telephones, security cameras, and customizable wall finishes. The basic elevator algorithm determines the most efficient path for an elevator to travel based on remaining requests in each direction.