A network port is a virtual point where network connections start and end. It allows different applications on a computer or device to communicate over a network, such as the Internet. Each port is identified by a unique number, ranging from 0 to 65535, with some numbers reserved for specific services, like HTTP on port 80 or HTTPS on port 443. When data is sent over a network, it travels through these ports to reach the correct application. This organization helps manage multiple connections simultaneously, ensuring that data is directed to the right place without confusion.