What are the basic ingredients of a chocolate bar?

Well first, chocolate bars contain cocoa. Cocoa comes in two forms: cocoa solids and cocoa butter. These are 2 products of processing cocoa mass, which is pure chocolate in its rough form. Baking chocolate is a combination of cocoa solids and butter.

Sweet chocolate is what we usually eat. It's chocolate with sugar added to it. There's three types of sweet chocolate: white, milk and dark.

Milk chocolate is sweet chocolate with milk added to it.

White chocolate is the same as milk chocolate, except cocoa solids aren't used, only cocoa butter. I don't know how they keep the finished chocolate as a solid instead of it melting though.

Finally, dark chocolate is sweet chocolate without milk.

Other ingredients are often added to chocolate, too. Soya lecithin is one. I had to look up the meaning of 'lecithin', it basically means fat. I'm not sure why soya fat is added to chocolate. Maybe it's because fat is tasty, and soya fat is particularly cheap fat.

So in summary: