The Internet is the global network of computer networks that use the ?TCP/?IP protocol suite to communicate. Sometimes, even wider definitions have been used; for example, any computer that is reachable by Internet ?email could be said to be "on the Internet" even without an IP address.
The Internet routing technology was originally based on military requirements, i.e. nuclear attack survivability. The possibility for non-hierarchical and decentralized routing makes the network quite resilient.
However, many other key aspects of the Internet are somewhat centralized (e.g. the tree-like way of dividing the global IP address space or coordinating the DNS hostnames). The currently dominant resource access technology, the WWW, is particularly oriented around centralized servers and thus lacks the resilience of the underlying network.
Matter and energy
The energy and material requirements of the Internet-related infrastructure are of particular concern to permacomputing.
TODO: Include information about research on the energy requirements of data transmission etc.