Responsive Design is a technique used in web design that allows to design and program pages in such a way that the layout, size and visibility of elements changes as the browser window size changes.

Typically responsive pages have several predefined breakpoints each targeting specific type of devices (laptop, tablet, smartphone). At each breakpoint pages are designed to look their best and thus provide the best experience to the users.

Responsive design should not be confused with Adaptive design when completely different pages are served depending on the target device and window size.