What are web services?
Web services are functions that are deployed on one server and can be called remotely from any other system. Calling functions remotely is not something new, it was always a primary concept in building distributed systems. Dozens of methodologies and protocols were invented to support remote function calling—CORBA, IIOP, DCOM, and many other technologies are good examples of the idea. However, web services have gained popularity and domination over all of those, and we will soon show why.
The basic idea of web services is very simple, and can be summarized in three steps:
- You write a function
- You deploy the function on a web server
- You assign the function a unique URL
For example, if you need to use a function that lists a set of products of another system, you may write this function, deploy it on some server, and give it the following URL: http://example.com/products.
If you open this URL in a web browser, you should see a list of all available products. It's very similar...
