Bus is a group of wires that connects different components of the computer. It is used for transmitting data, control signal and memory address from one component to another. A bus can be 8 bit, 16 bit, 32 bit and 64 bit. A 32 bit bus can transmit 32 bit information at a time. A bus can be internal or external.
· Data bus
Data bus carries data from on component to another. It is uni-directional for input and output devices and bi-directional for memory and CPU.
· Control bus
Control bus carries control signal. CU of CPU uses control signal for controlling all the components. It is uni-directional from CPU to all other components.
· Address bus
Address bus carries memory address. A memory address is a numerical value used for identifying a memory location. Computer performs all its task through the memory address. CU of CPU sends memory address to all the components. So, address bus is also uni-directional from CPU to all other components.