What is a web service in relation to supplier creation in oracle

We are creating controls for supplier creation to reduce the amount of duplicates. In our research we noticed that Web Service is one of the creation sources where a lot of duplicates were created. We are trying to determine what causes suppliers having web service as their creation source.

We are also trying to determine the differences between creation sources that are Web Service, Import, and Registration. We have searched knowledge docs and could not find an answer.