Thanks @robinhaney
Actually, Web design isn't front end, front end is a web developer
Web design is about how you can resolve the client's problem designing layouts for web and stuff. It's important for web designer to know HTML and CSS (Javascript too, but maybe not's too much) for create layouts for front end can coding your layout you know and not's wasting time creating layouts that front end can't coding your layout. And, also, if you're interest to become a freelancer it's important to know coding. But web designer isn' t a front end developer, it's important to know the differences.