An endpoint is a defined destination or source for data within a device, most commonly a numbered channel in a USB device through which a specific type of data flows in one direction.
In practice
A USB headset may expose separate endpoints for incoming sound to the earpieces, outgoing sound from the microphone and button presses on its cable. The audio class driver opens the sound endpoints while the input class driver reads the button endpoint.
Common confusion
In audio settings, Windows also uses endpoint for any input or output a user can select, like Speakers or Headphones. That meaning is related but higher-level. Endpoints are not physical ports; one connector can carry many endpoints.
Why it matters to readers
Recognising endpoints explains why one physical gadget can appear as several devices in Windows, each with its own driver and settings.
A closer look
USB endpoints come in different transfer types suited to different jobs. Isochronous endpoints deliver steady streams such as audio with guaranteed timing but no retries; bulk endpoints move large amounts of data reliably when time permits; interrupt endpoints handle small, frequent reports like key presses. Drivers choose the type that matches each kind of data the device produces.
