3 small qestions , plz help

Hi all ,

I’ve three small MySql qeus. :

what does " [COLOR=blue]single precision[/COLOR]" means and what’s [COLOR=blue]double precision[/COLOR] ?

what’s the [COLOR=blue]fixed point[/COLOR] and what’s [COLOR=blue]float point[/COLOR] ?

and finally plz anyone simplify [COLOR=blue]double vs float[/COLOR] in mysql " in practical use " ?