You've probably heard the phrases "responsive design" and "mobile-friendly" tossed around the boardroom--and with good reason, too. You see, the web is progressing quickly toward putting more emphasis on good user experience (and less on tables and beveled buttons) and it has been for quite some time. Not only are Google's algorithms shifting to favour content that users enjoy the best (and interact with the best), businesses are feeling the pressure to make sure their site is working well for their customers.
That's the primary reason why businesses are concerned with investing in a responsive or mobile website: user experience. If the usability of a site is low, you can bet the user rate follows suit; think of user experience (in this topic) as an extension of your customer experience. With the growing percent of all web traffic coming from devices of all widths and capabilities, it's become increasingly more important to make sure your users (customers and potential customers) are able to access your site easily regardless of their device.
There are a couple ways to address this issue, primarily the following two: you can build a website that is responsive, meaning that it will function (through varying its layout) on any device, or you can build a separate mobile website--in addition to your existing company website--for your mobile users.