Networking & Internet

Socket

Definition

A network socket is an internal endpoint for sending or receiving data at a single node in a computer network. Concretely, it is a representation of this endpoint in networking software. It is a combination of an IP address and a port number.

Why It Matters

Sockets are the programming interface for network communication. When a developer wants to create a network application, they use the socket API provided by the operating system to create, connect, send, and receive data.

Contextual Example

A web server application creates a "listening socket" on port 80. When a client request arrives on that port, the server "accepts" the connection, which creates a new socket dedicated to communication with that specific client.

Common Misunderstandings

  • A socket is defined by the combination of a protocol, a local IP address, a local port, a remote IP address, and a remote port.
  • Socket programming is the fundamental way to write network-aware applications.

Related Terms

Last Updated: December 17, 2025