A pod's way in. Everything you cord into the pod's box from outside flows through a PodIn and appears on its outlet inside - one PodIn per pin on the pod's box, in the order they were made.
The port's editor re-classes it in place between Mono, Stereo, MIDI and Video, keeping its name so every cord survives; the pod's box grows matching pins. Add more from the pod canvas's right-click menu.
A Video port carries no sound. Video cords are pure topology - the frames are put together on screen, not in the audio graph - so the port simply passes what reaches it on to whatever is corded from it inside.