HTML, or Hypertext Markup Language, is the standard code used to create email, webpages, and other digital documents. HTML is made up of a series of elements that are used to structure content. For example, the element indicates a paragraph, while the element indicates a heading. CSS, or Cascading Style Sheets, is a code that helps to improve the appearance of HTML documents. CSS can be used to control the color, font size, and layout of a document. JavaScript is another popular code that can be used to create interactive webpages. JavaScript can be used to add images, audio, and video to a webpage. Marketing professionals often use HTML to create email campaigns and landing pages. By understanding how HTML works, marketing professionals can create more effective digital marketing materials.