When Alfresco released version 1.4, it made a huge leap forward in enterprise readiness. That was the release when Alfresco embedded the JBoss jBPM engine into the product, which meant that enterprises could route Alfresco repository content through complex business processes. In 2010, Alfresco launched Activiti to replace JBoss JBPM. Activiti can be used embedded in Alfresco, but also as a standalone. For a while, Alfresco supported both jBPM and Activiti as an embedded workflow engine. However, from the latest 5.x version, jBoss is considered as deprecated and shouldn't be used.
Most content has some sort of process around it. That's why content repositories almost always have a mechanism to streamline, facilitate, and report against the business processes that produce, consume, or transform the content within them.
But before geeking out on the wonders of graph-based execution...