# Rooms and devices

> You talk to rooms. Devices are the Cymos that see them.

## Rooms

A room is a space you name, such as "Bedroom" or "Ward 3, bed 2". The API refers to it by an opaque `room_id` such as `room_bedroom`, separate from its name, so you can rename it without breaking anything. Almost every read takes a `room_id`, because that is what your product cares about: what is happening in this space right now.

## Devices

A device is one Cymo, with a `device_id` such as `dev_bedroom`. When you pair a Cymo in the dashboard you place it in a room. Move it later with `PATCH /v1/devices/{device}` and your code keeps working, because it still asks for the room, not the device. An offline device is reported as offline, never as an empty room.

## More than one Cymo in a room

On the Professional plan, several Cymos can share a room. Cymatics fuses them into one view, so you still get one snapshot per room with each person listed once. Pass `view=device` to see what each Cymo tracked on its own.