It describe light colour. Warm White is a softer more yellow light that is closer to the light given off by a traditonal halogen spotlight .Therefore warm white is better suited for living rooms.
Cool white is a much brighter white that is closer to light given off by CFL bulb. It's best suited for commercial area. Daylight white colour is like light given off by a fluorescent tube.
Sometimes also interpreted as International Protection Rating, classifies and rates the degree of protection provided against the intrusion of solid objects (including body parts like hands and fingers), dust, accidental contact, and water in mechanical casings and with electrical enclosures.
The first digit indicates the level of protection that the enclosure provides against access to hazardous parts (e.g., electrical conductors, moving parts) and the ingress of solid foreign objects. The higher of this number, the better it can protect against hazardous parts.