\begin{definition}[Definition:Model of Class-Set Theory]
Let $V$ be a collection of objects.
Then $V$ is a '''model of class-set theory''' {{iff}} it satisfies the axioms of Von Neumann-Bernays-Gödel set theory.
Thus: 
:The elements of $V$ are then known as sets
:The subcollections of $V$ are known as classes.
\end{definition}