TGP teaches the language, its interpreter and some styles that can be used as building blocks for JS applications. TDG is a reference for the language, DOM imp

TGP teaches the language, its interpreter and some styles that can be used as building blocks for JS applications. TDG is a reference for the language, DOM implementations (which is a large portion of the book), tools and many aspects of the JS ecosystem. The Good Parts is concise and elegant; reading and practising it thoroughly will lead to a sound understanding of what makes JS a uniquely powerful language. Read both, but if you can only manage one make it TGP.