In both the physical and conceptual sense it's a mesh(/web). Physically it interconnects computers via wires in a web. Conceptually it connects ideas and information by use of hyperlinks(links for short) in a mesh. Both the conceptual and physical network are open, everyone can post ideas and links to ideas furthermore everyone can add computers to the web. It is interesting to note that the conceptual and physical internet are two separate things. There is no law binding the ideas in the internet (stored in, for example, html documents) to specific computers in the mesh. Nor is there a law stating that specific machines in the web should contain specific information. In a way the conceptual internet is distributed over the physical network the same way the pictures in a photo album are independent from the album itself.