The difference between critical section (the code that accesses critical resources in each thread) and mutex (mutex between processes, shared memory, virtual address)

Read this article today , I feel that the effect of critical area is similar to that of mutex , It's all about locking a piece of code , Let only one thread access , I don't know the difference ...
C Language multithreading foundation -02- A critical region , The mutex

difference ：

1、 Critical areas can only be used for mutually exclusive access between threads of objects in the same process ; Mutexes can be used for mutually exclusive access between object processes or threads .
2、 Critical areas are non kernel objects , Lock only in user mode , Fast ; Mutexes are kernel objects , Lock operation in nuclear mentality , Slow speed .
3、 The critical region and mutex are Windows Available on all platforms ;Linux Only mutexes are available under （Linux Only lock can be used under ）
Reference article ： The difference between critical areas and mutexes

About mutexes between processes （ The mutex ）, I don't understand , You can refer to this article ：

Linux Interprocess mutex （ Memory sharing ）

It is implemented by sharing memory , Calling pthread_mutex_init() Function time , The second parameter needs to pass in a property object （ State object ） The address of

Locks need to be defined on shared memory , About the creation of shared memory , You can refer to this article ：
Linux Shared memory encapsulation

in addition , Visible supplementary knowledge ：
LINUX Process variable isolation Virtual address