A Web service is a method of communications between two electronic devices over the World Wide Web.
It is also defined as a software system designed to support interoperable machine-to-machine interaction over a network.
In simple words, “Web services are developed to use by other software applications”
Web services communicate via either SOAP or REST messages.
REST stands for REpresentational State Transfer. It is a term coined by Roy Fielding in his Ph.D. dissertation
It is an architecture style for designing networked applications which typycally runs runs over HTTP.
REST is an architecture and not a “standard”. There is no w3c recommendation for REST. It is concept for better web and widely accepted.
RESTful applications use HTTP requests to post data (create and/or update), read data (e.g., make queries), and delete data. Thus, REST uses HTTP for all four CRUD (Create/Read/Update/Delete) operations.
It expects client to have knowlege of what to send and what to expect in response. It is focused on accessing named resources through a single consistent interface.
- It is simple
- It is lightweight and faster
- runs over HTTP
- Response can be returned in “XML/JSON” format