Without virtual environments, all your projects will use the same installed packages.

When you want to move a project to a server when it’s done, you don’t know which packages are needed for this project, so your only option is to also install all of those packages there. It will quickly become a long list and many of the packages won’t be necessary for that particular project.

When using a virtual environment, you have a set of installed packages for each project, and they don’t mix. Much nicer.

You can start using virtual env now. In your project directory, do:

pip install virtualenv  

Now you have the virtualenv command (for all projects).

virtualenv env

Now you have a directory “env” in your project directory that will contain this project’s virtualenv.

env\Scripts\activate

Now you are using this virtualenv (your prompt changed to reflect that).

pip install django

Installs Django only for this project.

pip freeze

Shows you which packages are installed, now only for this project.

pip freeze > requirements.txt

Creates a requirements.txt that you can use to remember which packages need installing, and as input for

pip install -r requirements.txt