What are the buses in the computer?

A very important one that has yet to be mentioned here is the address bus. It is used to identify what memory location is currently being 'addressed'. The value of the desired address is placed on the address bus and a read line is set to high. Once this happens the Northbridge gets the value at that address and places it on the data bus and sets a ready line to high. Once the CPU sees that this ready line is set to high it knows that the value on the data bus is what was at the address that the CPU wanted.

if you know what is PCB (Printed Circuit Board) and when you draw it you draw copper lines these line act as cables which signal move in it so this copper called bus

buses are a set of wires to carry 1s n 0s parallely between various components within the system

They are data buses for carrying highspeed data between different types of cards in your computer at very high speed. Graphics cards used to share the main data bus that the rest of the peripherals do but the bus speed quickly bacame a bottleneck. Then graphics card went to their own seperate bus first AGP and now higher speed PCIX.