Classes available in Divinity Original Sin 2 will be shown below. When starting the game, the player will create a character with different Origin and type. During this customization, many aspects of the classes can be altered - both gameplay choices (Attributes, Abilities, etc) and cosmetic choices (gender, skin color, hair style, portrait icon, etc). As in Divinity Original Sin Enhanced Edition, all characters start with 5 points in each Attribute. Each character gets 5 more Attribute points, 5 Ability points, and 2 Talent points to spend as they see fit.
All Ability points must be spent upon leaving the character creation screen, or else they are forfeited. This is to prevent a character from putting all of their Ability points in one skill, reaching skill level 3 by character level 2. In this situation, a character would be able to reach skill level 5 one character level earlier.
Choosing a particular class effects the starting gear and items a player has. In Divinity Original Sin 2, your class/origin in particular also affects your gameplay. Your background has varying consequences. While the extent of these consequences remains to be seen, it is evident from this video that it will affect dialogue choices and quests.