A network port is a common way of referring to three different things. Network access points, such as a home router, are often referred to as network ports. The second common meaning refers to the actual location where a network cable plugs into an access point or computer. These physical ports provide users with access to local area networks and the Internet. The last common usage for this type of port refers to the software system that allows computers to handle multiple network tasks at the same time. These ports split network traffic into a series of individual feeds so that information and services remain separate.
Wireless routers are often called network ports.
When users refer to a hardware network port, one of two things usually happens. A network access point, such as a router, switch, or modem, may be referred to as a port. This is especially common when talking about wireless networks, where the term ‘wireless port’ is used to refer to the router the system connects to. The other common hardware network port is the actual network connection. In this case, the small rectangular hole where the ethernet cable connects to your computer, router, or modem is the port. This usage is a holdover from older computer terms such as serial port or communication port.
A common type of serial cable is the recommended standard 232 cable (RS-232), often found in computers.
The ultimate use of the network port is software-based, not hardware-based. With this definition, a port is a non-physical, software-based location within your computer. These ports divide network traffic and network-based services into segments. The computer is able to individually prioritize and process these threads, just as it does with internal processes.
By splitting network feeds, a computer can send and receive from multiple sources at the same time. Each active network port is capable of receiving information directly. For example, if a process was running on port 1000, that particular network port could send and receive information. Outgoing information would have port 1000 referenced as the sender and information sent back would specifically go to port 1000. If a computer were holding a hundred different ports, they would all be doing the same thing.
In this situation, a network port follows certain guidelines on all computers. The port can be any number from zero to 65535, but many of the ports below 1024 are needed for specific Internet tasks. Processes such as web browsing, email, and telnet have predefined ports where the computer constantly monitors activity. Other programs, such as video games or program downloads, have user or program-defined ports that the computer only activates when the program is running.