Meaning of python -m flag

Question

What does -m in python -m pip install <package> mean ? or while upgrading pip using python -m pip install --upgrade pip.

Answer 1

From Python Docs:

Since the argument is a module name, you must not give a file extension (.py). The module-name should be a valid Python module name, but the implementation may not always enforce this (e.g. it may allow you to use a name that includes a hyphen).

Package names are also permitted. When a package name is supplied instead of a normal module, the interpreter will execute <pkg>.__main__ as the main module. This behaviour is deliberately similar to the handling of directories and zipfiles that are passed to the interpreter as the script argument.