Differences of Chocolate

What is the different of 

Dark chocolate, Milk chocolate, White chocolate and Couverture chocolate?

Dark chocolate

 Dark chocolate is chocolate liquor which as been fancied up a but with extra cocoa butter, sugar, emulsifiers, and flavorings. It retains a high percentage of cacao, 65% to as high as 99%. The higher the percentage, the less sweet the chocolate.

How to use it

Dark chocolate can be eaten out of hand, or used in recipes. It's a good choice for making a rich ganache, and can be used chopped for cookies. It is well employed as an ingredient in icings and glazes. Some dark chocolate can be quite expensive; reserve the really good stuff for recipes where the flavor will really shine. Refer to your recipe to know which type of dark chocolate is best; many recipes will give an indication.

Milk chocolate

Unlike dark chocolate, milk chocolate does contain dairy. While you might think it is infused with liquid milk, it's more commonly made by adding dry milk solids (think: powdered milk). At around 55 percent sugar and 20 percent cocoa butter, this creamy variety of chocolate is mild and quite sweet.

How to use it

Its high sugar content makes it decidedly sensitive to heat, so it may burn if you try to substitute it in recipes which call for semisweet chocolate. Milk chocolate melts easily, which is great when you're making a sweet treat like s'mores. Milk chocolate can be used when called for in a recipe, but is easiest to handle in no-bake recipes such as sauces, as a topping for already-baked treats, or fillings or icings.

White chocolate

Sugar, milk, and cocoa butter, but without the cocoa solids. Its ratios of cocoa butter, milk solids, and sugar are actually quite close to milk chocolate, but without the cocoa solids it has a creamy ivory hue.

How to use it

White chocolate's sweetness makes it a lovely addition to baked goods. Typically, if a baked good contains melted white chocolate, it will contain less sugar to make up for the sweetness.

White chocolate is wonderful as a candy coating or as a component of icings. It can even be used in ganache.

Considerations

White chocolate should not be substituted for dark or baking chocolate in recipes, as it has a different sensitivity to heat and may burn more rapidly. This post details the process of properly melting white chocolate.

Couverture

This is a type of chocolate which contains extra cocoa butter--to be labeled couverture, it must contain no less than 31%. The higher percentage of cocoa butter, when properly tempered, gives this chocolate a rich sheen and pleasing "snap". While traditionally couverture was dark chocolate, today it is available in milk and white chocolate varieties.

How to use it

Couverture's ability to attain high gloss makes it well suited to uses where it will be seen. It's ideal for candy coating and enrobing, and creating decorations which can be employed in cake decorating or as garnish.

Source : https://www.craftsy.com/blog/2014/11/what-is-the-type-of-chocolate-for-baking/