An electrical bus (sometimes spelled buss) is a physical electrical interface where many devices share the same electric connection. This allows signals to be transferred between devices (allowing information or power to be shared). A bus often takes the form of an array of wires that terminate at a connector which allows a device to be plugged onto the bus.

• Buses are used for connecting components of a computer: a common example is the PCI bus in PCs. See computer bus.
• Buses are used for communicating between computers (often microprocessors). See computer bus.
• Buses are used for distribution of electrical power to components of a system. The (usually) thick conductors used are called busbars. In an electrical laboratory, for example, a bare bus-bar will sometimes line the wall, to be used by the engineers and technicians for its high electrical current carrying capacity, which allows a convenient approximation to zero voltage, or ground in the US, and earth in the UK.
• In analysis of an electric power network a "bus" is any node of the single-line diagram at which voltage, current, power flow, or other quantities are to be evaluated. These may or may not correspond with heavy electrical conductors at a substation.

See also distributed generation, Switched-mode power supply; SMPS.