Compared to the black type, green olives are harvested earlier, when they are still unripe fruits, and still contain a lot of chlorophyll, to which they owe their green color. They are richer in water and mineral salts, they have a smaller fat content and are higher in antioxidants properties. Their pulp is usually firmer than black olives, because they need a shorter time in brine, before being ready for consumption.
Freshly picked olives have a very bitter taste, so they must be put in brine before being able to eat them.
The brine time for green olives is shorter than for black ones, just because they are less ripe.
Pitted green olives are more comfortable to eat, without the nuisance of the stone, but remember that they will be a little softer and even a little more salty, because they are processed with a double brine.