Cardamom normally refers to three types: green, white and black. The highly prized green cardamom is a green pod with dark-brown or black highly pungent seeds inside. White cardamom is bleached green cardamom and the seeds inside are black to light brown with a sharp, lighter refreshing flavor.
Black cardamom (also known as brown cardamom), though related, is not true cardamon. It is produced from the plants of the Amomum and Aframomum genus. Chinese cardamom (Amomum globosum) is dark brown and rather hairy. Black cardamoms are distinctly camphorous. The pods themselves are inedible and all the flavor is in the seeds. But the seeds can lose its their flavor and aroma quickly so its recommended to buy cardamom whole and grind or crush seeds when needed.
Cardamom is used to enhance both sweet and savory dishes. It is essential to many India spice mixes. In many South & Southeast Asian and Middle Eastern cuisines, cardamom is used in savory as well as sweet dishes. In Scandinavian dishes, its often used in breads and desserts.