Each dialog unit has a short-term memory made by session-persistent variables with local scope to the unit itself, but shared among all dialog units part of the same application.
In NaifJs each node is implemented as a stateless javascript function handler.
Variables are managed with specific NaifJs API primitives (getvar, setvar, etc.)
and they are stored in the session data storage.
Dialog unit variables must not be confused with slots or entities variables concerning input states pattern matching. For details see pattern matching doc.