Used to project future loads and potential problem areas. For example, a work group switch with several 10 Mbps ports usually will have a 100 Mbps uplink to a backbone switch or a server. Generally faster and cheaper than dedicated lines. A way to provide large memory spaces to processes. Virtual memory usually exceeds the actual memory capacity.
Virtual memory is broken into pages for ease of management.
Active pages are in memory, while the rest are on a disk. A network that interconnects multiple systems or networks over unlimited distances.