If you really want to know - google it, Fool.
Lighten up Francis...
Do you call everybody names? It must be wonderful to be around you. Imagine if everyone in the world spoke to one another as you do. Civility costs nothing and it makes you feel better and live longer.
I asked here because I knew from the wealth of knowledge here someone would explain it in terms that would not result in a visit from certain inquisitive people. One needs to be careful what one searches for on the web.