What is the point of a diffuser?

I hope you guys don't think I am stupid or anything, but I never really knew what a diffuser actually do. I heard everyone say to use it, but how? Also what is the point? what does it do to curls? If someone could answer me those questions that would be great. Thanks

A diffuser attaches to your blow dryer and instead of making it poofy(if youve ever used a blow dryer on your curls) from the air, it drys your hair wth out damaging your curls and making your hair frizzy. You have to use a heat gel though or moose with it though. You can learn how you use them and what you need by reading the instuctions on the box of one. They are quiet easy to work. HTH!