Hi:
If you are in the Predictive Modeling module of the SAS Academy for Data Science, then the Applied Analytics using SAS Enterprise Miner class will be useful. For example, in the Overview Lesson, there's a topic called "What is a Data Source?" and it shows this:
Also, this previous forum posting has a nice explanation of how the roles are initially set: https://communities.sas.com/t5/SAS-Data-Mining-and-Machine/Interval-amp-Nominal-Variables/td-p/33962... .
Then you'll find the Enterprise Miner documentation here: http://support.sas.com/documentation/onlinedoc/miner/index.html and this documentation page has a section on Data Source Roles and Model Roles: http://go.documentation.sas.com/?docsetId=emref&docsetVersion=14.3&docsetTarget=p0ldp4l9cnob3gn1dytm...
If you have a specific question about the Academy for Data Science classes, it's useful to know the course/lesson you have questions about. If you're not in the SAS Academy for Data Science, and just have general Enterprise Miner questions, there's another group in the Forum for Enterprise Miner users and it is here: https://communities.sas.com/t5/SAS-Data-Mining-and-Machine/bd-p/data_mining
Cynthia