Design that adapts automatically to screen size, so it looks right on phones, tablets and computers.
Responsive design means the same page rearranges its elements based on screen width. On a computer, products may show in four columns; on a phone, in one or two, and the top menu collapses into a menu button. You do not need a separate version for every device.
In many markets most visits now come from phones, and a page that needs zooming and sideways scrolling quickly loses a customer's patience. Search engines also take mobile-friendliness into account. Responsive design is no longer an extra; it is the baseline. Practical tip: test your app on a real mid-sized phone, not only on a desktop screen. Make sure buttons are large enough to tap, forms are easy to fill and Arabic text does not get cut off or overlap.