There are three types of MUSTARD seed: yellow, black, and brown. YELLOWMUSTARD seed, native to Canada, is the hottest of the seeds. English and French hot mustards are made primarily of yellow seeds. Mustard is used in pickling spice, marinades for meat and fish and adds a wonderful flavour to fish cakes. They are also used to make mustard!
BROWN MUSTARD (black mustard) is used extensively in Indian food and is generally fried in oil prior to using.