https://stackoverflow.com/questions/226108/what-is-a-web-service-in-plain-english
Answer 1
A simple definition: A web service is a function that can be accessed by other programs over the web (Http). To clarify a bit, when you create a website in PHP that outputs HTML its target is the browser and by extension the human being reading the page in the browser. A web service is not targeted at humans but rather at other programs.
So your PHP site that generates a random integer could be a web service if it outputs the integer in a format that may be consumed by another program. It might be in an XML format or another format, as long as other programs can understand the output.
The full definition is obviously more complex but you asked for plain English.
Answer 2
Simplified, non-technical explanation: A web serivce allows a PROGRAM to talk to a web page, instead of using your browser to open a web page.
Example: I can go to maps.google.com, and type in my home address, and see a map of where I live in my browser.
But what if you were writing a computer program where you wanted to take an address and show a pretty map, just like Google maps?
Well, you could write a whole new mapping program from scratch, OR you could call a web service that Google maps provides, send it the address, and it will return a graphical map of the location, which you can display in your program.
There is a lot more to it, as some of the other posts go into, but the upshot要点 is that it allows your application to either retrieve information FROM, or submit information TO some resource. Some other examples:
- You can use a web service to retrieve information about books at Amazon.com
- You can use a similar web service to submit an order to Amazon.com
- You could CREATE a web service to allow outside applications to find out about product information within your company
- you could create a web service to allow outside applications to submit orders to your company.