The operating temperature is the range of ambient temperature within which a power supply, or any other electrical equipment, operate in. This ranges from a minimum operating temperature, to a peak or maximum operating temperature, outside which, the power supply may fail.
The voltage level by which an electrical system is designated and to which certain operating characteristics of the system are related.
IP (or "Ingress Protection") ratings are defined in international standard EN 6529 (British BS EN 6529:1992, European IEC 659:1989). They are?used to define levels of sealing effectiveness of electrical enclosures against intrusion from foreign bodies?(tools, dirt etc) and moisture.