How is a computer able to perform tasks at the high speed?

Modern processors have a internal clock that is in orders of magnitude faster than standard time. Therefore, a computer is able to slice up tasks according to those tiny slices of time.

Take example, a processor running with a clock speed of 1GHz (1 billion clocks a second) and it can do 2 IPC (instructions per clock). This means it can run 2 billion instructions a second.