The monk is one of Dungeons & Dragons Fifth Edition's more unique classes. It's not an entirely mundane martial class, but neither is it a spellcaster like the wizard. Instead, they occupy a unique role, both mechanically and in the lore. D&D monks supplement their martial arts with mystical Ki, which gives them a versatile bag of battlefield tricks.
Source:https://www.cbr.com/best-dnd-monk-multiclass/