Calcium Carbonate vs Dolomite?

What is the difference between Calcium Carbonate and Dolomite? Which is better to use? I have always used dolomite before but I notice that the Calcium Carbonate was half the price of Dolomite.

Dolomite lime has calcium and magnesium and is a good pH buffer. Way better IMO.

Thanks for the information. I will use Dolomite since it also contains magnesium unlike Calcium Carbonate which is just calcium.