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Bootstrap-3 - Interview Questions
How many bootstrap 3 Grid sizes .!
These grid sizes enable you to change the layout of columns to best match different screen widths and devices__ the essence of responsive design.

xs  :  for the smallest screen widths like smartphones < 768 px
sm  : for small screen widths like smartphones and tablets >= 768 px
md  : â€Šfor medium screen widths like tablets and laptops >= 992 px
lg  :  for large screen widths like desktops >= 1200 px.