Associating pts and tty to a process

I am trying to find out which tty or pts is being run by which process. My research so far is that: - tty is a kernel or backend terminal to handle lower level stuffs - pts is a pesudo terminal to allow user to communicate with the system - there are a lot of tty and pts files in /dev but cannot be read Would like to ask the following questions: - Why does /dev/pts and /dev contains so much numbers (eg 1-26) despite ps -aux | grep pts only showing 4 pts entries - Is it possible to determine what process is running a pts or tty? As I read that ssh spawns a new shell, but not sure if its a pts or tty