Question

Write a difference between a user-level thread and a kernel-level thread?

Answer 1

The operating system has various differences between the User Level and Kernel Level Threads are as follows:

Features	User Level Threads	Kernel Level Threads
Implemented by	It is implemented by the users. It is implemented by the OS.
Context switch time	Its time is less.	Its time is more.
Multithreading	Multithread applications are unable to employ multiprocessing in user-level threads.	It may be multithreaded.
Implementation	It is easy to implement.	It is complicated to implement.
Blocking Operation	If a thread in the kernel is blocked, it blocks all other threads in the same process.	If a thread in the kernel is blocked, it does not block all other threads in the same process.
Recognize	OS doesn't recognize it.	It is recognized by OS.
Thread Management	Its library includes the source code for thread creation, data transfer, thread destruction, message passing, and thread scheduling.	The application code on kernel-level threads does not include thread management code, and it is simply an API to the kernel mode.
Hardware Support	It doesn't need hardware support.	It requires hardware support.
Creation and Management	It may be created and managed much faster.	It takes much time to create and handle.
Examples	Some instances of user-level threads are Java threads and POSIX threads.	Some instances of Kernel-level threads are Windows and Solaris.
Operating System	Any OS may support it.	The specific OS may support it.