Bus structures can be somewhat confusing but at the same time it can help you understand most of the board. There are two type buses that you will find on the system board. There are internal and external. Below is a light description of both.
Internal- is basically the lines of communication of the board. The highway so to speak of the motherboard, its infrastructure. Looking at the board you will be able to recognize the bus by all the gold lines of wires running throughout board. A 64-bit bus is described as 64 wires or lines in the board. The idea of the internal bus is to transfer information across to all components of motherboard especially the external bus, which is covered later. What are the components of the internal bus and what lines are used for what? The control bus, Address Bus, Data Bus which are all located in the internal bus of the motherboard.
Control Bus- a signal that is sent by the CPU that coordinates actions of the system.
Address Bus- this is where data and instructions are sent from one component to another using the address bus. This is done by using memory location addresses to recognize the location of data in the system memory (RAM).
Data Bus- this is the lines or paths for actual data, instructions to be sent to components.
Power- this type bus is used to send power to components of the system.
The internal bus is just an internal line of communication sending data and instruction among itself. Not only this but providing power and addressing service for the system. Most of the time you don’t even think about this type of bus and it goes on in the background without your intervention. The funny thing about this bus is the dynamic properties of it. It almost seems that the motherboard should be more expensive than it is just for all the work it has to do.