BUS LINES: The data highways inside the computer through which the information moves from one spot to another.
a) Data bus wires actually carry the information around the inside of the computer.
b) Address bus wires carry the address of where the data is coming from or where it is going. This tells the various components in the computer whether they should receive data from or supply data onto the data bus wires.
c) Control bus wires carry information as to what to do with data, such as read or write or what kind of data it is. They also carry timing information to help synchronize the various parts of the computer so they are all doing the right thing at the right time.