Today, most trams use electrical power, usually fed by an overhead pantograph; in some cases by a sliding shoe on a third rail, trolley pole or bow collector.
If necessary, they may have dual power systems—electricity in city streets, and diesel in more rural environments.
Trams are now commonly included in the wider term "light rail", which also includes grade-separated systems.
Tram lines may also run between cities and towns (for example, interurbans, tram-train) or even countries (Basel, Strasbourg), or be partially grade-separated even in the cities (light rail). Some trams (for instance tram-trains) may also run on ordinary railway tracks, a tramway may be upgraded to a light rail or a rapid transit line, two urban tramways may be connected to an interurban, etc.
The tram was developed in numerous cities of Europe (some of the most extensive systems were found in Berlin, Budapest, Birmingham, Leningrad, Lisbon, London, Manchester, Paris).
The first tram in South America opened in 1858 in Santiago, Chile.
The identical word la trame with the meaning "crossbeam" is also used in the French language.
There are records of a street railway running in Baltimore as early as 1828, however the first authenticated streetcar in America, was the New York and Harlem Railroad developed by the Irish coach builder John Stephenson, in New York City which began service in the year 1832.
In late 1887 and early 1888, using his trolley system, Sprague installed the first successful large electric street railway system in Richmond, Virginia.
Within a year, the economy of electric power had replaced more costly horsecars in many cities.
Problems included the fact that any given animal could only work so many hours on a given day, had to be housed, groomed, fed and cared for day in and day out, and produced prodigious amounts of manure, which the streetcar company was charged with disposing of.
Electric trams largely replaced animal power in the late 19th and early 20th century.
The lines or networks operated by tramcars are called tramways.