Depends on the person: to some people, it's basically what's left of dancing when you pull choreography off the table - (1 - choreo) if you prefer equations.
I personally view it as the black and white principles of what's required to make execution of the dance look "correct" plus the grey area beliefs one chooses to incorporate to enhance the look of just the black and white topics. Dynamics, rhythm, space, lead/follow, design, choreography, and condition* are all separate disciplines under the framework I've been taught (connection and musicality are also separate and intentionally not studied specifically in the framework I've been educated under).
*Understanding of what's needed to make a particular technique happen or why a particular technique should be used is my best attempt to define this.