Mustard is a condiment made from the seeds of a mustard plant (white/yellow mustard, Sinapis alba; brown mustard, Brassica juncea; or black mustard, Brassica nigra).
The whole, ground, cracked, or bruised mustard seeds are mixed with water, vinegar, lemon juice, wine, or other liquids, salt, and often other flavorings and spices, to create a paste or sauce ranging in color from bright yellow to dark brown. The seed itself has a strong, pungent, and somewhat bitter taste. The taste of mustard condiments ranges from sweet to spicy.