describe the life circle of process:

As a process executes, it changes state.The state of a process isdefined in part by the current activity of that process.

new: The process is being created

running: Instructions are being executed

waiting: The process is waiting for some event to occur

ready: The process is waiting to be assigned to a process

terminated: The process has finished execution



 

why each process must have one PCB.

The process control block contains many pieces of information associated with a soecifi process,inluding Process state, Program counter ,CPU registers ,CPU scheduling information, Memory-management information ,Accounting information I/O status information.PCB serves as the repository for any information that many vary from process to process