The traditional types of chocolate are dark, milk and white. All of them
contain cocoa butter, which is the ingredient defining the physical
properties of chocolate (consistency and melting temperature). Plain (or
dark) chocolate, as it name suggests, is a form of chocolate that is
similar to pure cocoa liquor, although is usually made with a slightly
higher proportion of cocoa butter. It is simply defined by its cocoa
percentage. In milk chocolate, the non-fat cocoa solids are partly or
mostly replaced by milk solids. In white chocolate, they are all replaced
by milk solids, hence its ivory color.
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