If you are a proponent of Web services and follow discussions in the community, then certainly you must have come across the term REST. You probably have also seen headlines such as ‘REST vs. SOA’, ‘REST vs. SOAP’, etc. in magazines, blogs, and forums. While much of the talk around Service Oriented Architectures (SOA) has so far revolved around SOAP and the WS-* stack, recently REST based SOA (also called Resource Oriented Architectures - ROA) has started to silently permeate the Web.

What is REST?
The term REST is an acronym for Representational State Transfer. This term was coined by Roy Fielding, one of the principal authors of the Hypertext Transfer Protocol, in his doctoral dissertation. It is described as an architectural style for building distributed hypermedia systems and is manifested in the architecture of the World Wide Web. More commonly the term REST is also used to describe any simple interface that uses XML over HTTP without an additional messaging layer such as SOAP.

The Origins
The World Wide Web was conceived as an abstract space in which people and machines could interact. It would be chiefly populated by interlinked pages of text, images, etc. Information would be exchanged within this shared space with the users located around the world, creating and modifying it on heterogeneous machine systems.

Beginning with universities and research labs, the usage of the early Web soon grew to such an extent that the Internet developer community became concerned with this rapid growth. Along with some poor network characteristics of early HTTP, they feared this growth will quickly outpace the capacity of the Internet infrastructure and lead to a general collapse.