Some people believe that bitter and dark chocolate are, if not the same product, then at least there is no fundamental difference.
They are wrong. The main difference is in the composition.
Thus, dark chocolate contains fewer cocoa beans (40%-55%), while bitter chocolate contains more (at least 55%, often more than 90%).
In addition to cocoa beans, chocolate contains sugar, cocoa butter, natural flavors, fillers (nuts, dried fruits, etc.).
Dark chocolate contains less of these products, and bars with 99% cocoa content contain only one percent.
But the filling is not the difference between dark and bitter chocolate. As already noted, the cocoa beans will indicate which product is which.
They will also suggest cocoa butter (from 20% to 30% in dark, over 30% in bitter) and sugar (from 30% in dark and from 0% to 15% in bitter).
By the way, dark chocolate has more calories because it contains more sugar than bitter chocolate.
Important: the more cocoa beans there are in chocolate, the healthier it is.
Another difference between the varieties: black is sweeter and softer. Bitter has a more intense taste.
And they also differ in price. As a rule, dark chocolate is more expensive. But not always.
For reference
Chocolate is a confectionery product based on cocoa butter, which is a product of processing cocoa beans - the seeds of the chocolate tree, rich in theobromine and caffeine.