Port
The physical or logical connection on a computer which enables other devices, such as printers, modems, monitors, keyboards, and mice to interface with the computer.
HTTP (the main protocol to connect to the Web) is usually assigned to port 80.
An open, unprotected port allows intruders to get into your computer to install malware and to launch botnet attacks.
A router with a built-in hardwire firewall can help protect your port and your computer.