Russia´s First High Speed Train Sapsan, Moscow To St. Petersburg

Large cities often have a metro system, also called underground, subway or tube. The trains are electrically powered, usually by third rail, and their railroads are separate from other traffic, usually without level crossings. Usually they run in tunnels in the city center and sometimes on elevated structures in the outer parts of the city. They can accelerate and decelerate faster than heavier, long-distance trains.
The term rapid transit is used for public transport such as commuter trains, metro and light rail. However, in New York City, services on the New York City Subway have been referred to as "trains".
• Tram
In most countries, such as the United Kingdom, the distinction between a tramway and a railway is precise and defined in law. In the US and Canada such street railways are mostly referred to as trolleys. The key difference between a railroad and a trolley system is the latter running primarily on public streets, whereas trains have a right of way separated from the public. Often the US style interurban and modern light rail are confused with a trolley system, as it too may run on on the street for short or medium long sections. In some languages the word tram also refers to interurban and light rail -style networks, in particular Dutch.