Windows Server 2019 Administration Fundamentals - Second Edition

Understanding ports

In general, there are hardware and software ports. In a narrower context, a hardware port is any physical interface in a computer, peripheral device, or network device that allows interconnection for communication purposes. By contrast, a software port (often known as an application port) is any logical endpoint where applications from your computer communicate with other applications on other computers, both on LAN and WAN (or the internet). A web server uses ports 80 and 443 for the HTTP protocol and HTTPS protocol respectively.

The following table lists the well-known application ports:

Protocol	Port	Transportation protocol
FTP	21	TCP
SSH	22	TCP
Telnet	23	TCP
SMTP	25	TCP