On April 21st, Google rolled out a new version of their search algorithm specifically for mobile searches. Now, if Google thinks your website isn’t “mobile friendly” it’s not going to show up in searches done on mobile devices. This should NOT affect how your site performs on desktop/laptop searches.
You may also be hearing different terminology floating around like mobile friendly, mobile first, responsive design, adaptive design, separate mobile website (or m dot site) and mobile apps. Here’s a quick explanation of each type of mobile site experience.
A mobile friendly website is essentially when your regular website shrinks down to be small enough to display on a mobile device. It looks like a tiny version of your website. There’s a lot of zooming, pinching and scrolling going on, but the site displays and functions. It can be a less-than-ideal user experience, but at least your site is viewable. An example of this kind of website is sleepexperts.com.
Mobile first web design is when you start with a mobile website, and it is your primary company website. A good example of this kind of site is Uber. Or Foursquare. These are businesses that are exclusively (or almost exclusively) targeting a mobile user. The mobile site is the primary site and the desktop site is more of a landing page than a whole website.
Adaptive design is responsive with a twist. An adaptive website detects the device and delivers the appropriately sized website for the device being used. The main technical difference is that an adaptive site generally uses a predefined set of layout sizes based on device screen size rather than fluidly sizing down to fit. Ask.com is an example of an adaptive designed site.
Separate Mobile Site (or m dot site)
When an existing website can’t effectively be converted to a responsive site, a separate website can be built and is generally hosted on a subdomain. So if your regular, non-mobile site is http://mywebsite.com, then your mobile site could be http://m.mywebsite.com. A separate mobile site has its own HTML and doesn’t have to look like the main site. Facebook’s mobile site is an m dot site.
Large retailers like Amazon have both a mobile site and a mobile app to meet the needs of all of their mobile customers. A mobile app requires a user to download it from the app store and install it on their mobile device. Depending on the type of business and website, consumers may prefer an app over a mobile website experience, but that generally only applies to large brands that consumers visit regularly, and not to a retail or business site that they may only visit occasionally.