This shows the lifespan of the light source. Beamers need to have their lamps (light source) replaced every now and then.
Audible noise is the noise that a device produces while in operation. Reduced audible noise improves quality.
The width represents the horizontal dimension of the product. We consider a smaller width better because it assures easy maneuverability.
Volume is the quantity of three-dimensional space enclosed by the product's chassis or, in simpler terms, the space the product occupies.
The height represents the vertical dimension of the product. We consider a smaller height better because it assures easy maneuverability.
We consider a lower weight better because lighter devices are more comfortable to carry. A lower weight is also an advantage for home appliances, as it makes transportation easier, and for many other types of products.