When I was a child in London in the early 1900s, almost all commercial deliveries were by horse and cart, but passengers could travel on the roads by horse-drawn bus, horse-drawn tram or electric tram which received its power from overhead cables.
Trams ran on rails / tracks set into the road. Consequently they were not at all manoeuvrable: The driver couldn't steer them and other road users had to keep a constant look-out to get out of their way. Trams were particularly hazardous for cyclists because their wheels could easily get caught in the channels on either side of the rails unless the cyclists made a point of riding across them rather than along them. Fortunately, as it was expensive to lay the tracks, trams ran on relatively few routes.
My Aunt Em was one of the many women who was drafted in to work on the trams during World War One, when so many men were away fighting (or dead or injured). She often let us children have a free ride.
Double deck trams were usually drawn by two horses, as the photo shows. Single deck ones were usually drawn by a one horse. Horse-drawn trams were expensive to operate due to the required frequent changes of horse as well as stables, feeding, grooms etc.
The tram in the above image belonged to the then North Metropolitan Tramways. This company later became part of Metropolitan Electric Tramways and the former horse tram routes were electrified before becoming part of London Transport at the latter's formation in 1933. With the exception of three tram routes using the Kingsway Subway, all of North London's trams had gone by WWII and were replaced in the main by trolleybuses. London's remaining trams finally bowed out in July 1952, leaving London tram-less until the modern Croydon-based system appeared. During the last week of London's trams, many cars (as trams were called by staff) carried the announcement "Last tram week. On July 5th we say goodbye to London".
Trolley buses, which ran on wheels rather than rails were somewhat more manoeuvrable, but they did have to make contact with overhead cables for their power.
Buses and trams had open tops, and it was fun to sit on the top deck to see the scenery as it passed by. It could be cold though, particularly in a strong wind. Fortunately there were waterproof covers for passengers on the top deck for use in the rain. They were attached to the seat in front and could be unhitched to go across our knees.
Covered top buses and trams came into service sometime during the 1920s.