what is mean by class of col-xs-6

Hello Harikanth,

Usually columns are divided into 12 parts, so usually you can have 12 columns per row in the layouts.

Now,

xs = extra small screens (mobile phones)

There are other various similar possible options as below

sm = small screens (tablets)

md = medium screens (some desktops)

lg = large screens (remaining desktops)

So, when you apply col-xs-6 to any component its span to 6 columns on xs and sm.

Hope, this will help you to understand the concept. Feel free to write if you need more information on the same.

Don't forget to mark as answer if this helps.