A higher amount of cocoa solids indicates more bitterness. Semisweet chocolate is dark chocolate with low sugar content. Bittersweet chocolate is chocolate liquor to which some sugar (typically a third), more cocoa butter and vanilla are added.
The amount of cocoa solids directly correlates with the bitterness level in chocolate. Semisweet chocolate is a type of dark chocolate that has less sugar than other varieties. Bittersweet chocolate is created by combining chocolate liquor with additional ingredients like sugar, more cocoa butter, and vanilla.