Ryan Boudreaux includes all the code snippets you'll need in this demo of how to create an image hover-preview effect using HTML, CSS, and JavaScript.

CSS, or Cascading Style Sheets, defines the look and formatting of that HTML. Both are essential to coding your own website, and here's how to get acquainted with them.

We’ll use three essential tools: HTML, CSS, and JavaScript (see graphic). Each plays a crucial role in making your site pop.