title: What is a "modern browser"?
body: <p>I searched SO before asking this potentially vague question, found many references to 'modern browsers', but no definitions. Since this is a term very widely used and referenced, I was surprised that I couldn't find a definition or even a description on the Internet. </p>
  
  <p>So, what, in June 2018, is considered a modern browser? And what is a modern browser in general, is it only the current major version of each popular browser (i.e. Chrome, Safari, FF, IE, Opera)?</p>