Do I need to make a virtual environment?

[Pedroski55]

I run Ubuntu 18.04

I read I can create a "virtual environment" for Python 3 with:

python3 -m venv /path/to/new/virtual/environment

I only do simple things.

Do I need to run Python in a virtual environment?

My friend uses Windows, poor guy. Can he run Python in a virtual environment in Windows??