Both the olives mentioned here are the processed forms of olives but there is some basic difference between them. The type of olive is decided by the timing when you are taking them to get processed.
The fruit of the plant olive as inedible in its raw stage and to make it edible you have to take it through processing. There are two stages of the fruit at which it can be processed; either it is processed while it is ripened or unripe. When the fruit is being processed unripe it produces green olives and when take it to get processed while it is ripe it produces black olives.
You can find various uses of both kind of olives and the prime use of green olives is in martini while black olives are used mostly with pizza, some Mexican foods and salads made in the Mediterranean-style
The fruit of the plant olive as inedible in its raw stage and to make it edible you have to take it through processing. There are two stages of the fruit at which it can be processed; either it is processed while it is ripened or unripe. When the fruit is being processed unripe it produces green olives and when take it to get processed while it is ripe it produces black olives.
You can find various uses of both kind of olives and the prime use of green olives is in martini while black olives are used mostly with pizza, some Mexican foods and salads made in the Mediterranean-style