Q1：What is the purpose of Process?

Ans：A process is a block of a program that performs certain functions and specifies that the CPU can only execute sequentially within a process, that is the process is a unit that can execute concurrently.

Q2：Describe their relation and difference for process and program.

Ans：

1. The process is dynamic, the program is static——The program is a collection of ordered code, the process is the execution of the program.

2. The process is temporary while the program is permanent——A process is a process of state changing, and the program can be saved for a long time。

3. Process and program components are different. Process components include programs, data, and process control blocks (i.e., process state information).

Q3：Why the status of process is divided into five states, not other numbers,such as 4,7?

Ans：As a process executes, it changes state. The state of a process is defined in partby the current activity of that process. Aprocess may be in one of the following 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.

These names are arbitrary, and they vary across operating systems. The states that they represent are found on all systems, however. Certain operating systems also more finely delineate process states. It is important to realize that only one process can be running on any processor core at any instant. Many processes may be ready and waiting, however.