• Computer communications occurs through the computer bus.computer image by blaine stiger from Fotolia.com
  
  The term bus, in computer language, refers to a system within the computer hardware that moves data. Without buses, the computer may do calculations, but lacks the ability to move the resulting data to any form of output device. Buses fall into several categories and types. The computer bus is sometimes referred to as the address, local, or data bus. The bus is also sometimes called the Peripheral Component Interconnect.
  
  

Internal Computer Bus

• Data movement between devices internal to the computer occur through the internal bus. This function includes transferring information between such devices as the video card, the random access memory or the hard disk.
  
  

External Computer Bus

• Data movement outside the computer occurs through the external bus. This can include devices such as Small Computer System Interfaces (SCSI), printers or even monitors.
  
  

Bus Types

• Buses are either serial or parallel. Parallel buses move data in multiple bits, with several individual bits moving on parallel paths. Parallel buses can come in several sizes. Serial buses move data one bit at a time, in a series, through the bus.
  Either type of bus can be used in external or internal bus applications.
  
  

Bus Speed

• The speed of the bus is often referred to as the computer's speed. The device will work no faster than its ability to move data from component to component within the device or from the computer to external components. Bus speed is measured in megabytes per second, often referred to as MBps. This translates to a million bytes per second. Seven or eight bits, each bit a single binary one or zero, make up a byte. The eighth bit, if present, comprises the parity bit and is used to check the validity of the byte. The faster the computer's internal bus speed, the better the performance of the computer.