A garden is a metaphor for a lot of things: growth, persistence, and the continuation of life.
The Garden is an old metaphor associated with hypertext.
Every walk through the garden creates new paths, new meanings, and when we add things to the garden we add them in a way that allows many future, unpredicted relationships.
There is no right or canonical way to view it
A hard part of this is The Navigation Problem: how do we give web users just enough guidance to freely explore the web, without forcing them into pre-defined browsing experiences?