Dependencies declared in your project's pom.xml file often have their own dependencies.
The dependencies such as dom4j, javaassist, JBoss logging are considered as your project's transitive dependencies.
The very important key benefit of Maven is that it automatically deals with transitive dependencies and includes them in your project.
The main dependencies are called direct dependencies.
And the sub dependencies on which the direct dependencies relied on are called transitive dependencies.
You have a direct dependency called Hibernate Core, and the Hibernate Core requires JBoss Logging, dom4j, javaassist etc to function properly.