Dungeons & Dragons Fifth Edition has 13 character classes after the artificer's introduction in Eberron: Rising from the Last War. Players are spoiled for choice when it comes to what they want to play. However, this hasn't always been the case. The original Dungeons & Dragons game limited players to just three class options.
Source:https://www.cbr.com/dungeons-dragons-original-fighter-wizard-cleric-classes/