一、流程：
进程是执行程序的活动。进程有两种类型——用户进程和系统进程。进程控制块控制进程的操作。
2. 内核线程：
内核线程是一种线程，其中进程的线程在内核级别进行管理。内核线程由操作系统调度(内核模式)。
进程和内核线程的区别：
| PROCESS | KERNEL THREAD |
|---|---|
| Process is a program being executed. | Kernel thread is the thread managed at kernel level. |
| It is high overhead. | It is medium overhead. |
| There is no sharing between processes. | Kernel threads share address space. |
| Process is scheduled by operating system using process table. | Kernel thread is scheduled by operating system using thread table. |
| It is heavy weight activity. | It is light weight as compared to process. |
| It can be suspended. | It can not be suspended. |
| Suspension of a process does not affect other processes. | Suspension of kernel thread leads to all the threads stop running. |
| Its types are – user process and system process. | Its types are – kernel level single thread and kernel level multi thread. |