Basically mobile version of a website is an alternate version of a website that is optimized for use on smartphones or similar mobile devices. By default, a mobile version of a website is already a mobile optimized website.
Today’s mobile devices are mostly touch-based. Compared to desktop and notebook computers, they have small screens with limited screen resolution. As technology and innovation improved, smartphones became more powerful, affordable and now are more common than regular cell phones. The touch-based nature of these phones created a different way to surf the web. It’s the same as using a regular web browser on your desktop but yet it’s a bit different.
Have you ever been to a non-mobile optimized website on your smartphone and tried to click on a link but had a really hard time because the link is too small or too close to other links? Having a mobile version of the website would solve this problem by using a different layout made specifically for mobile devices such as smartphones.