Google now has a Google Developers website dedicated to mobile website design. The site offers a simple Mobile Friendly Test. Mobilized and responsive sites are more easily viewed on mobile devices, and in April Google started a new campaign to favor mobile friendly sites in their search results — presumably this will be a greater priority for searches done from mobile devices.
If your website is hosted with WordPress.com, there are already responsive and mobile design features built in. For fun, you can test your site using Google’s Mobile Friendly Test. In your website Dashboard under Appearance > Mobile, try the test after turning ‘Enable mobile theme’ on, and then try the test with the mobile theme off. If you’re using a modern theme like the Twenty Fourteen them, you’ll see a preview that shows you the difference between mobile and responsive.
If you’re using WordPress with a self-hosted website through a company like Blue Host, Dream Host, GoDaddy, or others, then you can install and activate the Jetpack plug-in. It has a Mobile option. You’ll need to connect Jetpack to a WordPress.com user account (setup a free account if needed). It’s best to be logged into WordPress.com and the from your website Dashboard, click on the option to Activate Jetpack. Once activated, find the Mobile Theme option under JetPack and Activate it. You can then perform the tests described in the paragraph above.
A website with responsive design adjusts and changes layout depending on the width of the window. So, even on a desktop computer, the site pages will look different as you make the window wider or narrower. On tablets and smartphones, the responsive design will adjust accordingly. In most cases your site will retain much of the same look and feel as the desktop version, although menu options may disappear into a menu button, and some elements like full-width images or banners may get smaller and then disappear as the window width narrows.
A mobilized website doesn’t necessarily change in the desktop view. However, on a mobile device, the site may have a completely different appearance than the desktop version. All the work you put into the desktop version may not even show up in the mobilized version. Mobilized sites may look like a smartphone app.
Choosing Responsive or Mobilized
Your choice of responsive or mobilized will depending on what you want the user experience to be. A mobilized site may be a bit more simplistic and lack some of the nicer graphic design elements of the desktop version. As described above, a responsive site may be more visually appealing. It depends on your preference.