Fahrenheit is the standard temperature measurement for America (and maybe some other parts of the world, I don't know for sure). Water freezes at 32*F and boils at 212*F. If you live in America, these are the numbers you are used to and can relate to. (You know that 95* is hot, but still bearable....whereas 95*C would kill you!)

Celcius is the more scientific measurement used and is the standard for most of the world. Water freezes at 0*C and boils at 100*C.