n Introduced to obtain a systematic way of monitoring and controlling pgm execution n A process is an executable program with: u  associated data (variables, buffers…) u  execution context: ie. all the information that F  the CPU needs to execute the process • content of  the processor registers F the OS needs to manage the process: • priority of the process • the event (if any) after which the process is waiting • other data (that we will introduce later)