OK, say you have some code that gave you weather predictions, maybe the UK's MET Office has one.
Then companies like BBC, can use this in weather.bbc.co.uk to display the weather.
Maybe a uni exposes a web service with some very complex cool maths functions. This means developers can connect and use the functionality.

OK, here's a good one. MSN Messenger 7. Instead of using winsock I believe it uses a web service. Much better way of connecting, and much easier.

Also, say you have a web app, and a windows app, that use the same functions...both can connect to the web service, or the win32 app can use the web service to expose functions from a DLL on the web server.

There are loads of wb services out there. Most are free, some you have to pay for. There is a web site that is like a phonebook for free web services. Trying to think what it is. Nope it's gone. Will look for you.

Woof