TCP/UDP ports

What is a TCP/UDP port?

A TCP/UDP port is a 16-bit number (a value between 0 and 65535) used to identify an endpoint of a network communication on a computer system. These ports are used together with the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP), two of the most common communication protocols on the Internet.

The combination of an IP address and a TCP or UDP port number is used to direct network traffic to the right service or application on a device or server. Each port number is usually associated with a specific service or application on the system. For example:

• Port 80 is commonly associated with HTTP web traffic.
• Port 25 is used for outgoing e-mail (SMTP).
• Port 53 is used for domain name resolution requests (DNS).
• Port 22 is associated with the SSH protocol for secure system administration.

TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) are two of the most widely used transport protocols on the Internet. TCP is a connection-oriented protocol that guarantees data is delivered in the right order and handles retransmission in case of loss or error. UDP, on the other hand, is a connectionless protocol that guarantees neither delivery nor order, but is faster and more efficient for applications that do not need reliable communication, such as real-time video streaming or online games.

In short, TCP/UDP ports are numbers that let network devices and servers identify which services and applications incoming and outgoing data are meant for, making communication and routing of data on a network easier.

List of the most common TCP/UDP ports