I have Ubuntu 20.04.

python3 --version this command showed that Python's version is 3.8.10.

I haven't changed (added/deleted) any modules/folders that belong to Python, it's in the default configuration.

I wanted to know whether all the modules in the standard library of Python is pre-installed in my computer. If not all modules of the standard library are installed, what's the reason for it (is it that only libraries that require for the Ubuntu to run are installed and rest are ignored)?

Edit:

I changed my question: Do I have everything that I get when I install python by Downloading it from python.org, pre-installed?