# Where does the name 'Ens$_V$' come from?

The book I'm reading describes Ens$$_V$$ as:

Where $$V$$ is any set of sets, the category with objects all $$X \in V$$, and arrows all functions $$X \rightarrow Y$$, with the usual function composition.

• What does the name Ens$$_V$$ come from?
• What is it short for?
• How do you refer to it in speech?