How does CSS work? When a visitor loads one of your Web pages, by either typing in the address or clicking a link, the server (the computer that stores the Web page) sends the HTML file to the visitor’s computer along with any files linked to or embedded in the HTML file. Regardless of where the CSS code is, the visitor’s browser will interpret it and apply it to the HTML to render the Web page using that browser’s particular rendering engine that is then displayed in the browser window.

The margin of an element allows you to set the space between that element and other elements in the window by specifying one to four values that correspond to all four sides together, the top/ bottom and left/right sides as pairs, or all four sides independently. To define the margins of an element: 1. Start your declaration by typing the margin shortcut property name in the declaration block, followed by a colon (:) margin: 2. Type a value for the margin.