Answer from cs61c-cf (Aspandiar Dahmubed 16812056) for Question 2
A set of  parallel conductors, which allow devices attached to it to communicate with the CPU.The bus consists of  three main parts:                                    Control lines, address lines and Data lines. Control lines allow the CPU to control which operations the devices attached should perform, I.E. read or write.
Address lines allows the CPU to reference certain (Memory) locations within the device. Data lines allow the meaningful data which is to be sent or retrieved from a device is placed on to these lines.