We said that a bus uses parallel transfer — the bus contains multiple data lines,
and can simultaneously transfer one bit over each data line. Thus, if a bus contains K
data lines, the bus can transfer K bits at a time. Using the terminology from Chapter
13, we say that the bus has a width of K bits. Thus, a bus that has thirty-two data lines
(i.e., can transfer thirty-two bits at the same time) is called a thirty-two bit bus.