Howdy Steve S,

Delta blues is that accustic rattly slide stuff where the singer hollers the words. The kind of stuff that gets you in your throat when you listen to it.

Chicago blues is up beat, electric and has some really great blues harp lead and harmony parts. It ususlly has some drums and is played by combos like rock and roll.

Texas bluEs is a mix, mostly delta roots mixed with some electric mixed with some red hot chili peppers.

Delta is Missippi Fred McDowell Chicago is Muddy Watters Texas is Stevie Ray Vaugn

And many others!