Until five years ago, designers assumed that users accessed their site on a computer screen. /the concept of safe-size tablet grids were developed to assure that the pages appear in full width on every comuter monitor.
However, things have changed lately. More than half the population access the web via their smartphones or tablets. This has made the concept of safe size grids irrelevant. We cannot any longer talk about safe size grids because screen sizes range from 380px in smartphones to 2800 px on computer monitors.
Hence a new way of designing pages has been developed knownas responsive web design. Using CSS stylesheets, responsive webpages change their layout to fit into the screen of the user.
Alex Calvert WMU School of Communication, Kalamazoo Michigan
June 21, 2016