Green Cardamom has a light, sweet flavour. Its distinct flavour is often used in desserts such as Kulfi and other Indian sweets. In addition, green cardamom is often thrown into curries. It has a light flavour, and adds a slightly flowery fragrance. You can add the pods whole to a curry, but it is usually better to crush them with a rolling pin or mortar and pestle before use, to release the flavours. Each pod contains several little tiny seeds.
Black Cardamom is stronger than green cardamom, and is usually added into curries or rice. Black Cardamom is also a common constituent of garam masala, where it is crushed together with the other spices to make the familiar blend. You can also pop a few whole black cardamoms into rice, where the boiling process really releases the flavours into the rice.