ok well first of all, the alto and bari are in the key of Eb while the tenor and soprano are in the key of Bb. they all have the same range from the low Bb to the high F (three ledger lines up) with some exceptions. for more info go here:
http://www.wfg.woodwind.org/sax/index.html where you will find a fingering chart for the sax. they vary in size, soprano being the smallest and the bari being the largest. the alto, tenor, and bari are used in concert and marching bands. all four are usually used in jazz. they arent used in a symphony orchestra except for solos. um, thats all i can think of for now. if you have more questions just post and i or someone else should be able to help you.
