Confused by official mongodb documentation, what is socketTimeoutMS?

The time in milliseconds to attempt a send or receive on a socket before the attempt times out. The default is never to timeout, though different drivers might vary. See the driver documentation.

The socketTimeoutMS sets the number of milliseconds a socket stays inactive after the driver has successfully connected before closing. If the value is set to 360000 milliseconds, the socket closes if there is no activity during a 30 seconds window.