A Node Is Really A Network Port

A node is really a network port. The nodes are divided into two categories: "node of transition" and "node of access". The purpose of the "node of transition" is to support network connection, which transfers and transmits information through communication lines, such as network ports of switches, gateways, routers and firewall devices. The "access node" is the source point and target point of information exchange, which is usually the network card interface on the user's computer. For example, when we design a network system, we usually say that there are multiple network ports to configure IP address in the network.