Definition
A sensor is one of the basic resources in Matter that allow you to dress a product. Sensors are used to specify view-related information, such as the aspect ratio and type of projection, and to group 2D elements applied to a rendering.
To use a sensor, you must assign it to a camera or to a viewport. Assigning a sensor to a viewport assigns it to the viewport's free camera. You can assign a sensor to as many cameras as you would like.
Sensors are managed in the Matter sidebar's 
sensor library.