The Nintendo 64 is a 64 bit machine as the name implies. The Super Nintendo (SNES) was only 16 bit. Compare it to a freeway. Say for example a freeway with eight lanes is a bit like a 8 bit computer. You can send 8 cars (or data) through the machines central processing unit simultaneously.
Think of a 64 bit machine with 64 lanes with 64 bits of data at one time. |