Metros, short for metropolitan trains, are rapid transit systems designed to transport large numbers of passengers within urban areas. They typically operate on dedicated tracks, allowing for efficient travel between city neighborhoods and suburbs. Metros are known for their frequent service and can help reduce traffic congestion in busy cities. Most metro systems consist of multiple lines, each identified by a color or number, and connect various stations. Major cities around the world, such as New York City, London, and Tokyo, have extensive metro networks that serve millions of riders daily, making them a vital part of urban transportation.