Charisma measures your ability to effectively interact with others, including your confidence and eloquence, as well as the power of your personality (be it charming, commanding, or forceful).
Your Charisma score applies in the following situations:
Charisma is used in social situations to determine first impressions, to fit in or stand out, and to influence others.
Some examples of Charisma checks include:
The Bard, Paladin, Sorcerer, and Warlock all use Charisma as their Spellcasting Ability Modifier, which helps determine their Spell Attack Bonus (how easy it is to hit other people with spells) and Spell Save DC (how hard it is for creatures targeted by their spells to resist their effects).