It was invented at CERN by Tim Berners-Lee, and developed here from 1990 to 1994.
Roads are different, but all interconnected.
This is very similar to mailing an envelope with an order to a company, which then ships the goods back to you. WWW is a client-server system with both clients and servers spread all over the world. You can now look at the document as long as you like, there is no traffic going on. It is like if you ordered a book by post and have received it. The documents are on server computers.