A trolley is a vehicle that runs on rails or tracks, usually powered by electricity from overhead wires. In many American cities, trolleys carried passengers along city streets from the late 1800s through the mid-1900s. San Francisco still runs its famous cable cars, which are similar street vehicles that grip an underground moving cable. In other countries, people often call these vehicles trams or streetcars.

Unlike trains, which run on separate railway lines, trolleys typically share the road with cars and pedestrians, stopping frequently to pick up passengers. They make a distinctive clanging sound with their bells to warn people they’re coming. Many cities tore up their trolley tracks in the 1950s and 1960s when buses became more popular, though some cities are now bringing trolleys back because they move lots of people efficiently without creating pollution from engines on the vehicles themselves.

In British English, a trolley is what Americans call a shopping cart: the metal basket on wheels you push through a grocery store. The British also use trolley for the wheeled carts that flight attendants push down airplane aisles.