We know that intersection of vertical and horizontal lines create grids. Bootstrap’s grid system divides the screen into multiple rows (horizontal lines) and columns (vertical line). Grid system is the most important feature of bootstrap and it's biggest advantage is that, it is responsive unlike HTML tables, means it is flexible and adjusts itself in all screens because of this feature it is used for responsive web design. The default Bootstrap grid divides the screen into 12 columns in each row. You can add CSS classes to block elements in the HTML document by using bootstrap grid system.


Bootstrap is an open source front-end framework to develop responsive websites. You cannot create a mobile-friendly and responsive website without the grid system. Sites designed responsively are generally fluidBootstrap designs. The fluid grid system uses percentages instead of pixels for column widths. This framework is developed by Twitter and available free at GitHub. You just need basic knowledge of web technologies (HTML, CSS and Javascript) to build dynamically adjustable web pages with the help of bootstrap. It based on grid system and provides a variety of pre-defined components which are not only useful for novice web developers but also a boon for expert coders. Bootstrap allows experts to customize it and create a something new with the help of Less and Sass.

In today's technological world it may seem that everyone has a website or web page. The web has become an essential part of everyday life. We can assume that a business , regardless of its size, will have a website. Normaldevices display sizes websites do not fit to different screen sizes. Every website owner wants to reach maximum public to gain maximum output from his/her website. We have desktop monitors, LCDs, laptops, mobiles and tablets.

So, we need a solution that would work on all screen sizes. As we know "Necessity is the Mother of Invention", and this necessity, caused to invent Responsive Web Design (RWD). It is a buzz word in web design circles. With the help of responsive design we can solve very real problem about how and where website will be accessed.