Question with getfenv()

Someone please help me. I dont know what envinronment is getfenv(0) and what is getfenv(1)? can someone tell me? is env 0 local? I am trying to loadstring using customized module and env there automatically sets to getfenv(2) by default

I have Never used getfenv() before but looking at the docs might help? According to it:

“If provided with an integer, getfenv() will provide the environment of the function at the provided stack level: Level 1 is the function calling getfenv(). If stack is 0, getfenv() returns the global environment of the current script. When using getfenv() to get the current environment of a script, it will return the same table every time within the specific thread.”