Culture - Whats the deal with Skunk???

[Chronix]

So SWIM lives in the US and has been using this forum for a few months, latley however he has been seeing many posts about High Grade Marijuana being called Skunk. The term itself is not un-known to SWIM but it was always used for names of individual strains, like "Lemon Skunk" and stuff like that, not as an almost "umbrella term". SWIM realized after awhile that these references have been being made by people in the UK. Around here this high quality weed has just always been called Chronic so where did the "Skunk" lable come from??