Processes are introduced to enable multiple processes to execute concurrently, while improving resource utilization and system throughput
1.the process is dynamic, while the program is static.
2. the process has a certain lifetime, and the program is a set of instructions, itself has no "movement" meaning. A program that does not create a process cannot be recognized by the operating system as a separate unit.
3. A program can correspond to multiple processes, but a process can only correspond to one program. The process is to the program what the play is to the scr ipt.
4. Different processes and procedures. From the static point of view, the process is composed of program, data and process control block (PCB). A program is an ordered set of instructions

Because the process must go through five different states-new,running,waiting,ready and terminated, these five steps construct a complete process, if there is any state lost, the process won’t finish.