I am new to website design. Anyone help me to find the solution of my question ?
Every grid system is worse than the next
The grid system is derived from methods of old-fashioned photo-typesetting for offset printing. It is based on fixed size paper and is totally inappropriate for the web.
In grid systems, ID and CLASS tokens are non-semantic and are presentational, a Bad Thing. Further, multiple tokens on an element are endemic. If you need to apply more than two classes to an element, you don't know what you're doing and the developers of the various grid systems do not know what the hell they're doing. For example:
<body class="single single-post postid-148839 single-format-standard custom-background mp6 customizer-styles-applied group-blog highlander-enabled highlander-light">
Since you are new to the web, go to the htmldog site for their tutorials. They teach best practice. Do not pollute your mind with that grid crap. Once you know what you're doing, you may look into grids, if only so that you can maintain or debug the crap work of others.