0 a computer network that uses the internet but can only be joined by people who have permission or who have the right software:
The concept of a darknet is a hidden underground where people anonymously and securely communicate and share files with each other.
Groups can rapidly join and share in a darknet and leave just as easily.
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.