A network socket is a software structure within a network node of a computer network that serves as an endpoint for sending and receiving data across the network.

The API for the network protocol stack creates a handle for each socket created by an application, known as socket descriptor. In Unix, this descriptor is a type of file-descriptors. It is stored by the process for use with every read and write operation on the communication channel.

At the time of creation with the API, a network socket is bound to the combination of a type of network protocol to be used, a network address of the host, and port number.

An application can communicate with a remote process by exchanging data with TCP/IP by knowing the combination of protocol type, IP address and port number. This combination is often known as a socket address. The remote process establishes a network socket in its own instance of the protocol stack and uses the networking API to connect to the application, presenting its own socket address for use by the application.

References

• https://en.wikipedia.org/wiki/Network_socket
• differences-between-unix-domain-sockets-and-network-sockets