Project directory: one for all?

Hello everyone,

This is my first post and I am currently learning through the Front End Engineer course path.
This is a rather general question but I hope I can explain myself well. I am currently going through Getting Started with Text Editors which talks a bit about folders and organization.

I wanted to know what is the best way to approach the “main folder”. I am currently having a traineeship like to learn on the job, but I wanted to know:
Is there one folder for all projects? From work related to personal?
Or do you/should you separate them for better organization? How does this affect the managing of directories?

Hope this has been clear and thank you in advance!