Responsive / Mobile Design is far important now then it was before as over half of Internet Traffic is done on Mobile and Tablet Devices. Having one Website being accessed through different Devices and Computers is now the industry Standard. It is the process of Content Planning, UI and UX Design, Implementation, and Testing across the various numerous Devices and Browsers.
Google set a line in the sand on April 21, 2015 with their Mobilegeddon. Google started to boost the rankings of Responsive / Mobile Websites and penalize the Website that were not "Mobile Friendly".
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