How does a responsive theme work?
A responsive theme is a WordPress theme that adapts to different screen sizes. Themes are coded using CSS and JavaScript, but some themes are built to be responsive by default, while others can be made responsive through plugins.
The main purpose of a true responsive design is to optimize the user experience for all the devices people use to access your site. A user’s engagement with a site on their desktop computer is likely very different than it would be on their smartphone’s smaller browser window or tablet device’s larger screen. A good example of this can be seen in how people hold up mobile phones while they read an article—they tend not to hold them horizontally like they would do with a tablet or laptop (or even e-reader), but rather vertically so they can see more content at once (similarly, if you look at someone reading something on their phone while sitting down). To take advantage of these different viewing behaviors across various devices requires coding techniques that let the layout adapt accordingly so users don’t have trouble reading text or seeing images clearly anywhere from small smartphone screens all the way up through full HDTVs.