A mobile website is an optimized version of a full website designed for smartphones and mobile devices. It allows for easy reading and navigation on small screens using HTML, CSS, and other coding languages. The mobile site is typically located on a subdomain and accessed via a smartphone's web browser. A mobile app, on the other hand, is downloaded from an app store and runs as a native application on a specific device type. Building a mobile-optimized website is less expensive than creating native apps and allows content to reach users on any mobile device with a browser.