进程级线程和用户级线程的区别

1. 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. 用户级线程：
根据级别，线程有两种类型：

1. 用户级别
2. 内核级别

用户级线程是一种在用户级管理进程的线程的线程。用户线程由线程库(用户模式)调度。

进程级线程和用户级线程的区别：

PROCESS	USER LEVEL THREAD
Process is a program being executed.	User level thread is the thread managed at user level.
It is high overhead.	It is low overhead.
There is no sharing between processes.	User level threads share address space.
Process is scheduled by operating system.	User level thread is scheduled by thread library.
Blocking one process does not affect the other processes.	Blocking one user Level thread will block whole process of the thread.
Process is scheduled using process table.	User level thread is scheduled 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 user level thread leads to all the threads stop running.
Its types are – user process and system process.	Its types are – user level single thread and user level multi thread.
Each process can run on different processor.	All threads should run on only one processor.
Processes are independent from each other.	User level threads are dependent.
Process supports parallelism.	User level threads do not support parallelism.