What is REST, and Why Does It Matter?

by Tom Welsh

While Web services undoubtedly have much to offer, their significance is chronically confused by the misleading name with which they have been saddled. Perhaps we will never know who decided to exploit the huge popularity of the Web by enlisting its name. Viewed purely from a PR perspective, this was a masterstroke, guaranteeing instant and lasting media interest. It can also be taken as expressing the aspiration that, one day, Web services will be as pervasive and useful as the Web itself.

It is not yet clear how big the overlap really is between Web services and the interactive ("first-generation") Web. One of the best sources of insight into this common ground lies in Representational State Transfer (REST), an "architectural style" described by Roy Fielding in his celebrated Ph.D. dissertation, which has become one of the canonical Web documents. Many full and frank discussions have arisen from comparisons between REST and SOAP (especially when the latter is used in RPC style), and it is fair to say that familiarity with REST is a prerequisite for understanding much of today???s leading-edge thinking about Web services. So this issue of WSS is devoted to REST and its implications.