A wait state is a situation in which a computer program or processor is waiting for the completion of some event before resuming activity. A program or process in a wait state is inactive for the duration of the wait state. For example, an application program that communicated with one other program might send that program a message and then go into a wait state until it was "reawakened" by a message back from the other program.
When a computer processor works at a faster clock speed (expressed in MHz or millions of cycles per second) than the random access memory ( RAM ) that sends it instructions, it is set to go into a wait state for one or more clock cycles so that it is synchronized with RAM speed. In general, the more time a processor spends in wait states, the slower the performance of that processor.