How to implement type checker in Python using MyPy?

I am exploring static type checker for Python and came across different packages while setting up Visual Studio Code.

I could do,

pip install mypy

pip install mypy-lang

pip install pyls-mypy

All the above three works. But, what is the difference between mypy, mypy-lang and pyls-mypy packages?

I have installed python-language-server for linting and formatting. And I came across mypyls.exe executable.

The documentation at https://github.com/palantir/python-language-server mentions that the pyls-mypy plugin will add extra functionality to the python-language-server

1. Which of these is used for enabling the Type-Checker (or all the 3 are needed)?
2. Are these packages in any way related to the python-language-server ? If yes, how ?