What is the Difference Between a Stone Mill and a Steel Mill?

What is the Difference Between a Stone Mill and a Steel Mill/Colloid Mill?

Similarities: 

Both are tools for grinding grains or oil crops.

Differences:

Stone mill: Low-temperature and low-speed grinding will not destroy the nutrients in grains/oil crops. The ground products are all natural, without any whitening agents and preservatives, with good taste and high nutritional value.

Steel mill/colloid mill: fast grinding speed and high efficiency.