In UBIK, a ContentClass is a single instance of a certain [[MetaClassMetaclass]]. When created, this instance inherits all [[MetaPropertyMetaproperty|MetaProperties]], [[Attribute|Attributes]] and programmed behavior from its MetaClass.
Each and every of the inherited MetaProperties results in a [[BasePropertyBaseproperty]] at the ContentClass, and these Properties can now hold distinctive values for this very instance.