Hyperloop is a proposed high-speed transportation system for both passengers and freight. In 2013, the concept was published by businessman Elon Musk in a white paper, where the hyperloop was described as a transportation system using capsules supported by an air-bearing surface within a low-pressure tube. Hyperloop systems have three essential elements: tubes, pods, and terminals. The tube is a large, sealed, low-pressure system. The pod is a coach at atmospheric pressure that experiences low air resistance or friction inside the tube using magnetic propulsion. The terminal handles pod arrivals and departures. The hyperloop, in the form proposed by Musk, differs from other vactrains by relying on residual air pressure inside the tube to provide lift from aerofoils and propulsion by fans; however, many subsequent variants using the name "hyperloop" have remained relatively close to the core principles of vactrains.
