RWD is the new standard for modern website development. RWD stands for Responsive Website Design. The concept is simple: Create a site that scales down properly for all screen sizes. This alleviates the necessity of having to build different sites for your two largest audiences, namely computer users and mobile users. A responsive website tailors the information layout automatically for smaller laptop screens, pad, large cell phones and smaller smart phones, no separate site required.
The design is fluid, shifting information around, scaling graphics, and even removing art elements as the site requires as the target viewport gets smaller and smaller. It is important to know that you want a RWD site from initial concept as the design has to be able to adjust for the change in screen size. Then you have to take the time to develop the fluid changes needed as the scale shifts in size.
There are many companies out there that say they create "responsive" sites, but many have their own definition of what that means. If you want to see if a site is truly RWD. Just grab the bottom right corner of your browser and watch what happens to the site as you shrink the window. If you get left or right scroll bars, the site is not RWD.