i// is a typically sweet, usually brown, food preparation of Theobroma cacao seeds, roasted and ground, often flavored, as with vanilla. It is made in the form of a liquid, paste, or in a block, or used as a flavoring ingredient in other foods. Cacao has been cultivated by many cultures for at least three millennia in Mesoamerica. The earliest evidence of use traces to the Mokaya (Mexico and Guatemala), with evidence of chocolate beverages dating back to 1900 BC. In fact, the majority of Mesoamerican people made chocolate beverages, including the Maya and Aztecs,[who made it into a beverage known as xocolātl [ʃoˈkolaːt͡ɬ], a Nahuatl word meaning "bitter water". The seeds of the cacao tree have an intense bitter taste and must be fermented to develop the flavor.
(source : wikipedia)
Several types of chocolate can be distinguished. Pure, unsweetened chocolate contains primarily cocoa solids and cocoa butter in varying proportions. Much of the chocolate consumed today is in the form of sweet chocolate, combining chocolate with sugar. Milk chocolate is sweet chocolate that additionally contains milk powder or condensed milk. In the U.K. and Ireland, milk chocolate must contain a minimum of 20% total dry cocoa solids; in the rest of the European Union, the minimum is 25%. "White chocolate" contains cocoa butter, sugar, and milk, but no cocoa solids. Chocolate contains alkaloids such as theobromine andphenethylamine, which may have physiological effects in humans, but the presence of theobromine renders it toxic to some animals, such as dogs and cats.Dark chocolate has been promoted for unproven health benefits. ( source : wikipedia)
White chocolate, although similar in texture to that of milk and dark chocolate, does not contain any cocoa solids. Because of this, many countries do not consider white chocolate as chocolate at all. Although white chocolate was first introduced by Hebert Candies in 1955, Mars, Incorporated, was the first to produce it in the United States. Because it does not contain any cocoa solids, white chocolate does not contain any theobromine, so it can be consumed by animals.
Dark chocolate is produced by adding fat and sugar to the cacao mixture. The U.S. Food and Drug Administration calls this "sweet chocolate", and requires a 15% concentration of chocolate liquor. European rules specify a minimum of 35% cocoa solids. Semisweet chocolate is a dark chocolate with a low sugar content. Bittersweet chocolate is chocolate liquor to which some sugar (typically a third), more cocoa butter, vanilla, and sometimes lecithin have been added. It has less sugar and more liquor than semisweet chocolate, but the two are interchangeable in baking. ( source : wikipedia)