An Alfresco pipeline definition extends a pipline definition to add some extra Alfresco-specific properties.
A pipeline definition is sufficient to run a pipeline using the Componize framework, however, if you need to run a pipeline from Alfresco, then you will also have to create an extra Spring bean that defines some extra Alfresco specific properties. In Componize, we call this Spring bean an Alfresco pipeline definition. The Alfresco specific properties may include the content type to be used in Alfresco to store the options to be used by the pipeline.