<p>Web developers use these languages when they create a site:</p>

    <dd><em>HyperText Markup Language</em> describes the structure of the page and its contents.</dd>
    <dd><em>Cascading Style Sheets</em> describes how a site looks and even to some extent how it responds to certain events.</dd>
    <dd>JavaScript is the programming language used to define the logic and function of a site beyond simple look and feel. Any computation or "thinking" is done using JavaScript.</dd>