HyperText Markup Language (HTML) is the standard markup language used to create web pages. A markup language is your way of making notes in a digital document that can be distinguished from regular text. It’s the most basic building block you’ll need for developing websites. CSS (Cascading Style Sheets) is the language used to present the document you create with HTML. Where HTML comes first and creates the foundation for your page, CSS comes along next and is used to create the page’s layout, color, fonts, and…well, the style! Both of these languages are absolutely essential to being a front end developer. Simply put, no HTML/CSS, no web development.