I am a real fan of responsive web design, however there are many more sites (and books) that can explain the topic far better than I can (I’ll list a few at the end of the post).
In short, if you don’t know what it means, it is the idea of a site design that changes its layout depending on the device screen size that is viewing it.
With smartphones and tablets being so popular in the last few years, many more people are browsing the web on these devices, and providing an optimum design for these devices makes sites more engaging, easier to read and better suited to the device.
In my latest project I am working on at HigherSites, the project allowed me to work on some responsive web design, and here is a little demo, showing how the site will look on smaller screens, such as those on an iPad or iPhone:
Also, RWD means Rear wheel drive to most people (or is it just me?!) so I would refrain from referring to responsive web design as ‘RWD’.