Did you know.....why the IP rating of a lighting product is so important?
In brief, IP (Ingress Protection) ratings are defined in EN 60529 and simply defines the ability of an electrical product to seal and protect against the intrusion of foreign objects and water. (I) being the first numeral stands for intrusion of a foreign object, (P) being the second numeral stands for the intrusion of moisture.
As a guide IP20 rated products would be seen in interior spaces with no requirement for protection against the elements, where an IP65 product would be found in an exterior application which required substantial protection against the elements.