1.

As a process executes, it changes state. The state of a process is defined inpart by the current activity of that process. Each process may be in one of thefollowing states:

New. The process is being created.

Running. Instructions are being executed.

Waiting. The process is waiting for some event to occur (such as an I/O completion or reception of a signal).

Ready. The process is waiting to be assigned to a processor.

Terminated. The process has finished execution.

 

2.

PCB is a part of process entity and the most important record data structure in OS. It records all the information needed by OS to describe the process and control the operation of the process. The function of PCB is to make a program (including data) that can not run independently in a multi-programming environment become a basic unit that can run independently and a process that can run concurrently with other processes. In other words, OS controls and manages concurrent processes according to PCB. In the whole life of a process, the system always controls the process through PCB. That is to say, the system perceives the existence of the process according to the PCB of the process. So, PCB is the symbol of the existence of the process.