python modules, library differences in meaning

1.
modules:a collection of definitions of modules, functions, classes, variables, etc.
libraries:a collection of definitions of modules, functions, classes, variables, etc.
The word library is not specified in Python's language specification.It is used in a very large area.C's standard library or C#'s .net class library.A library is a generic program (API) written primarily for the purpose of being called by a programmer.
The module is designated as the Python language specification, so this one has a clearer meaning.Functions and classes are included.A module containing multiple modules is sometimes called a package in python, but internally it seems to be a module that organizes multiple files (modules).
2.
In this case, sklearn is a package, or a hierarchical module.
Pandas is a module with read_csv downstairs.
Both modules and modules are allowed.

import sklearn
import pandas
Type(sklearn)#->module but often referred to as a package
type(sklearn.model_selection)#->module
type(pandas)#->module
type(train_test_split)#->function