I have searched a lot upon internet but still i didn't get the clear difference between web services and web APIs? Somewhere I read that all web services are API's but all API' are not web services. How?
What all I know is both allow to utilize the functionality of other applications.Can someone describe me clear difference?
An API (Application Program Interface) is the interface through which another program can communicate with a program.
A web service in this context is one of those programs with an API. 'Web' means that it is accessible via the web, mostly via HTTP. A service usually has a well defined purpose.
For instance a date web service's purpose could be to provide the current date. The API of my service would have a single 'endpoint': get the date. The service then implements this API. It somehow retrieves the date and sends it back.