In responsive design, we will present the same web page that desktop or laptop computer users see to your mobile audience. Only the Cascading Style Sheets, or CSS, will be different. That is, browsers on desktop/laptop computers will render the page using one set of CSS instructions, while those on mobile phones another.
This method of working not only saves you the labour of creating a different set of pages for each type of user, but also the hassle of maintaining those 2 sets over the years, trying to keep them in sync.