This is just a general info question.

I currently have a 30 year fixed mortgage at 6%. While listening to the radio recently, an ad came on advertising a mortgage at 5.75%. Not a whole lot better, but enough to get my interest. Then, in the fast talk at the end of the ad, they said that the APR was 7.25%! Now, that made me lose all interest in the ad, but did get me to thinking. How is it that the can say the rate is 5.75, if the APR is 7.25? And when I say I have a 6% fixed, is that APR or whatever the first number is?