Term:bus« Back to Glossary Index
In computing, a bus is a connection between multiple components which allows those components to share information, power, or instructions relating to controlling those devices.
A common example is USB. The Universal Serial Bus interface is used to connect external (and occasionally internal) devices to a computer. Multiple devices are all connected to this one interface, and the electrical signalling on that interface determines which device or devices are in communication at any point in time.
Another example is the bus internal to the computer that connects the CPU to multiple banks of RAM and other internal components. While electrically very different than USB, the concept – that of connecting multiple devices to a single communication path – is the same.
A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a road vehicle designed to carry many passengers. Buses can have a capacity as high as 300 passengers. The most common type is the single-deck rigid bus, with larger loads carried by double-decker and articulated buses, and smaller loads carried by midibuses and minibuses while coaches are used for longer-distance services. Many types of buses, such as city transit buses and inter-city coaches, charge a fare. Other types, such as elementary or secondary school buses or shuttle buses within a post-secondary education campus do not charge a fare. In many jurisdictions, bus drivers require a special licence above and beyond a regular driving licence.
Buses may be used for scheduled bus transport, scheduled coach transport, school transport, private hire, or tourism; promotional buses may be used for political campaigns and others are privately operated for a wide range of purposes, including rock and pop band tour vehicles.
Horse-drawn buses were used from the 1820s, followed by steam buses in the 1830s, and electric trolleybuses in 1882. The first internal combustion engine buses, or motor buses, were used in 1895. Recently, interest has been growing in hybrid electric buses, fuel cell buses, and electric buses, as well as buses powered by compressed natural gas or biodiesel. As of the 2010s, bus manufacturing is increasingly globalised, with the same designs appearing around the world.