BootStrap allows four types of classes for column/Grid System.
.xs // for mobiles
.sm // for tablest
.md // for laptops and normal desktops
.lg // for larger desktop
Suppose i want to create a webpage/website which should be more resposive (definitely it must be) for all type of media. from mobiles to larger desktop. Can i use classes in this formate.
Note: In this example i am going to create left side column.
<div class="left-col col-xs-12 , col-sm-12 col-md-3 col-lg-3">
The following might be enough to achieve your goal
<div class="left-col col-sm-12 col-md-3">
It will use the full width when the device is a tablet or below. And it will use 1/4 of the width when its a laptop or larger desktop pc.