A system clock provides timing and scheduling for these operations. These days, many processing units, such as the FPU, are integrated right into the CPU chip. The processing units understand all the binary bits and bytes so that you don't need to. The processing units need to keep track of what they are doing by temporarily writing things down. RAM can be read and written to very quickly by the processing units.
RAM is only available while the computer is turned on and is cleared when the power is off.
This behaviour is just fine since it is only needed for temporary storage while the computer is processing. Storage Devices Storage devices are used to record anything that needs to be retrieved after periods when the computer is turned off. These are integrated circuit boards which plug in to expansion slots in your computer to provide additional functionality. The most common network cards provide this connection via Ethernet cable and are called Ethernet cards. In previous sections we talked about the anatomy of a computer.