1999 Toyota Camry, 114,990 miles, 4 cyllinder

I changed my timing belt at 60,000 miles per the instruction manual at an auto shop. A friend of mine just changed his serpentine belt on the exact same make and year car; are the serpentine belts and the timing belts the same thing? If you change the serpentine belt, do you still have to change the timing belt and can either one be done by regular people not in an auto shop?