This is a web design concept providing an optimal viewing experience with the same content for mobile phones, tablets, desktop computers.
RWD adapts a layout to viewing environment by using fluid, proportion-based grids, flexible images, CSS3 media queries.
AWD is basically the same as RWD.
The main difference is that the changes are made on the server side and not on the client side. That means the server (where website is hosting) detects the devices sending the requests to the server. The server sends different HTML and CSS codes based on the type of the device that have been detected.
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Responsive web design
Adaptive web design
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