CRI: Color Rendering Index: A measurement which rates how accurately are reproduced under a given light source.  <60 is poor, 70-79 is fair, 80-89 is good, 90+ is excellent, and 100 is considered "perfect ourdoors".  CRI's can only be judged between sources having the same color temperature.

A Kelvin rating suggests how warm (red) or cool (blue) a source of light is.

Imagine a blacksmith heating a horse shoe, the shoe first glows a dim red, then an orange, yellow, white, and blue white as the "temperature" rises.  Although it may be confusing at first, the higher the temperature, the cooler the color.

These are not actual hot-to-the-touch degrees in Kelvins.  
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