So what does this actually mean?
That your website works the same across all platforms – Desktop PC, Laptop, Mobile and Tablet and that the user doesn’t have to double tap or pinch your content to expand it, small text and line height limitations which make it hard for the user to accurately click on a link is a No No!!
Of course, there are many other rules that apply but your existing website can be easily converted over and cost is dependent upon the number of pages your current website has.