Responsive web design is just what it sounds to be, the ability of your website to adjust (respond) to any screen size your website is viewed on.
With responsive web design, your website layout will flex to fit the width of the device someone is viewing your website on, a mobile phone, ipad, etc. No more annoying zooming in and out to see the content of a non-responsive website.
Responsive web design is no longer a luxury in web design, it’s an expectation. Without a responsive website, you are losing out on better user engagement, greater lead generation and higher sales conversions from your website.
Google also considers a non-responsive website a negative SEO signal and or a negative user experience and your SEO ranking will drop to a competitor that has a responsive website.