HTML, CSS and JavaScript are the building blocks of the internet which are used to build all the websites around. HTML, or Hyper Text Markup Language, defines the layout of a webpage (where the headings go, what's the content that's displayed). CSS, or Cascading Style Sheets, define the styling of the website (what colours are used for each HTML component, whta font is used for text across the website). JavaScript is the main programming language that allows making your webpage interactive (clicking a button opens a box, filling in a form sends the information to a server).