Biological networks
Biological networks resemble many types of man-made networks, types of systems of diverse structure and function, each a collection of parts, the parts themselves differing in type, with multiple copies of each type, parts capable of interconnecting, the interconnections tying all the parts together into a whole entity made up of subtructures and modules of subtructures, the interconnected parts capable of interacting, the interactions capable of producing particular changes in the structure of each other or in the structures' properties, enabling intercommunication with signals that convey information, the whole structure a functional unit designed for a purpose.
Biological networks differ from such man-made networks, however, in having no human designer, having emerged from nature by organic evolutionary processes, its foundational system a biological cell, a biocomputer, designed basically to live and reproduce itelf, autonomous, capable of cooperating with other cells to generate multicellular structures that can intelligently design networks, inorganic as well as organic ones.