모든 is adjective. 모두 is noun. 모든 사람들이 그를 좋아한다. All people like him. 모두 그를 좋아한다. Everybody likes him. I hope it will help. thank you !

모두 is a noun or adverb. 모든 is what is called a pre-noun, so it's kind of like an adjective and needs to have a noun after it. So 우리 모두 = "all of us"; 모든 종류 = "all kinds".