T46 Dec 24, 2025 2 min read

Network socket

An OS-managed endpoint for network communication, represented as a file descriptor in a process.

Definition

A network socket is an OS-managed endpoint for network communication.

In Unix-like systems, sockets are represented as file descriptors inside a process.

What you do with sockets

At a high level:

  • servers create a socket, bind it to an address and port, and listen for connections
  • clients create a socket and connect to a server
  • both sides send and receive bytes

Why sockets matter for debugging

A large set of “network bugs” are actually socket-level realities: ports in use, permissions, timeouts, connection resets, and resource exhaustion.