From Computer Science Wiki
This page is linked to networks and networking. [1]

In computer networking, a port is a communication endpoint. At the software level, within an operating system, a port is a logical construct that identifies a specific process or a type of network service. Ports are identified for each protocol and address combination by 16-bit unsigned numbers, commonly known as the port number. The most common protocols that use port numbers are the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP).[2]

I like the analogy that an IP address is like an address to a big apartment building, and a port is the address of a specific apartment within the building.



A network socket is an internal endpoint for sending or receiving data within a node on a computer network.[3]

A TCP socket is an endpoint instance defined by an IP address and a port in the context of either a particular TCP connection or the listening state.

A port is a virtualisation identifier defining a service endpoint (as distinct from a service instance endpoint aka session identifier).

A TCP socket is not a connection, it is the endpoint of a specific connection.

There can be concurrent connections to a service endpoint, because a connection is identified by both its local and remote endpoints, allowing traffic to be routed to a specific service instance.

There can only be one listener socket for a given address/port combination.[4]


This video is perfect to give you a very basic idea of sockets: