What exactly is a module as defined by Gradle dependencies?

This SO question http://stackoverflow.com/questions/21764128/how-do-i-exclude-all-instances-of-a-transitive-dependency-when-using-gradle caused me to wonder what exactly is a Gradle module then? I can understand the Maven notion of groupId:artifactId:version, which I understand translates to group:name:version in Gradle. But then, how do I know what module (in gradle-speak) a particular Maven artifact belongs to?

Thanks --Jens

For a Maven dependency, ‘module’ corresponds to artifact ID.