A computer bus is characterised by the amount of information that can be transmitted at once. This amount, expressed in bits, corresponds to the width of the bus, i.e. the number of physical lines over which data is sent simultaneously. A 32-wire ribbon cable can transmit 32 bits in parallel. The term "width" is used to refer to the number of bits that a bus can transmit at once.
Additionally, the bus speed is also defined by its frequency (expressed in Hertz), the number of data packets sent or received per second. Each time that data is sent or received is called a cycle.
This way, it is possible to find the maximum transfer speed of the bus, the amount of data which it can transport per unit of time, by multiplying its width by its frequency.
A bus with a width of 16 bits and a frequency of 133 MHz, therefore, has a transfer speed equal to: 16 * 133*10^6 = 2128*10^6 bit/s.
Also if I understand correctly, a signal/data transmitted in a computer bus is actually an electrical current with its electricity frequency. The power supply unit on the power chord for a computer is a AC->DC converter, so is the electricity frequency zero in computer buses?
I wonder if the bus frequency and the electricity current frequency are the same concept? If not, how are they related?
Also if I understand correctly, cables such as USB cables and Ethernet cables are also computer buses. So the above questions are asked for them too.