Difference between web services and web application

Question

Lets have an example scenario:

Client opens a web site and finds the sum of two numbers which he enters from the textboxes.Then clicks on the ADD button.Two parameters a

Answer 1

I'd say that web applications are intended for users and web services are intended for other applications. That's the most important difference. Web applications usually present data in HTML which looks nice to the user and web services usually present data in XML which easy to parse by other applications.