Is that a "thread" consists of both "user thread" and "kernel thread" as two parts?
And when I create a "thread", is that I create a "user thread" and another "kernel thread" is created "in the background" by OS also?
I'm confused because of the second picture.
The book I'm reading is "Operating System Concepts, 9th ed., SILBERSCHATZ", and it's at page 169. Thanks a lot