I\'ve been reading about \"web services\" here on SO, on Wikipedia, Google, etc., and I don\'t quite understand what they are. What is the plain English definition/descript
The best plain English explanation comes from using an analogy:
Your PHP example is a web service by that definition, because the output could be consumed by another program. But in reality, HTML screen-scraping is not a reliable or maintainable way of producing web services.
Web Service is like a medium of commuication between two unrelated programs. The programs use a specified protocol(Usually Simple Object Access Protocol (SOAP)) as medium to understand what REQUEST/RESPONCE they are to process/execute on there respective end.
Without prejudice to other definitions I would say that a web service is software system that allows for inter-operable machine-to-machine / application-to-application interaction over a network. This generic definitions would also help consider REST architectures to be a web service as they provide similar functionality albeit being an architectural style unlike the SOAP which is a fully defined protocol.
'Web Service' is composed of two words,'Web' and 'Service'.
What is 'Web'? 'Web' means 'World Wide Web'.
'Service' for what? Not for Human,if so,it's 'Web Page',such as text,images,video etc.
It's for Programs to communicate through the Internet using the same technology the 'Web' used,such as TCP,HTTP etc.
'Service' also means it provides some functions,like the 'Service Layer' in CRUD.
There are mainly two types:
1. SOAP(Simple Object Access Protocol)
2. RESTful(Representational state transfer)
A simple definition would be an HTTP request that acts like a normal method call; i.e., it accepts parameters and returns a structured result, usually XML, that can be deserialized into an object(s).
In simple words Web service could be any simple program ex: add two numbers which should be published over the UDDI and can be consumed by another program.WSDL will have the endpoint to locate the webservice and also the binding and port details.