What was the major difference between the models of Democritus and Aristotle?

Democritus believed that matter was made up of indivisible particles called atoms, which differed in shape and size, leading to the diversity observed in nature. Aristotle, on the other hand, proposed a continuous matter theory where substances were composed of combinations of the four elements (earth, water, air, fire) and did not believe in the existence of indivisible particles like atoms.