To be more precise, the bus transfers bits from the CPU to memory, from memory to the CPU, from input devices to memory, and from memory to storage devices.

Like a freeway, the bus is also divided up into "lanes." Each lane can carry 8 bits or 1 character of information. A two-lane or 16-bit bus transfers 2 characters at a time. A four-lane or 32-bit bus can transfer 4 characters at a time. Finally, an 8 lane or 64-bit bus can transfer 8 bytes at a time.

How does this work in your PC? Let's say you have a four-character number stored in RAM that needed to be to be transferred to the CPU:

If your PC has a 16-bit bus, the transfer would take two steps: 2 characters the first time and two the second, because a 16-bit bus has only two lanes and can only transfer 2 characters at a time.

If you PC has a 32-bit bus the transfer would take one step. Why? Because the 32-bit bus has four lanes and can transfer 4 characters at a time.

The 32-bit bus is able to transfer data faster than the 16-bit bus, because it has more lanes. It can transfer the data in one step, whereas the 16-bit bus requires two steps. The fewer the steps, the faster the data moves. The faster the data moves, the faster your PC.