I'm learning about web services and most of the resources I've been reading talk about registering your web service once it's ready for use by others. Is registering a web service required to use the service?
For example, let's say I have a web application on a company intranet and I create another web service app that retrieves some sort of useful information to be displayed on this private intranet site. Would this new web service require being registered just so my web app can use it or can the web app simply interface directly to the new web service (following the WSDL file) without the need of some sort of UDDI registry?
You can certainly use the service without the UDDI registry.
I have created several Web Services and have immediately used them without registering them. Registration gives others confidence that your Web Service is legitimate and descriptions of how to interact with those services.
Imagine doing development where you have to register any Web Service before using it. Yikes!