Communications and networks
Understanding the general principles of computer networking has a conceptual foundation. System administrators unfamiliar with general networking principles need to read this topic. Those familiar with UNIX networking can safely skip this topic.
A network is the combination of two or more computers and their connecting links. A physical network is the hardware (equipment such as adapter cards, cables, and telephone lines) that makes up the network. The software and the conceptual model make up the logical network. Different types of networks and emulators provide different functions.