Your site may be viewed on a wide variety of devices. Although it is possible to build a separate site for phones and other small devices, in most cases the best approach is to use responsive design.
A responsive design adapts to the width of the screen. A single HTML file provides any given page, regardless of the device. The CSS code uses a statement called a media query to trigger different styling based on the screen width.
Most of our SmartThemes are based on Twitter Bootstrap and provide a complete initial setup for a responsive site, ready for your customization.
See our Bootstrap Resources page to learn more about creating responsive designs.