Equilibrium
From Rice Wiki
The equilibrium solution of an ODE is a value where y will not differ over time.
Stability
An equilibrium is stable if slight perturbations from the equilibrium solution will not drastically change y.
In contrast, an equilibrium is unstable if slight perturbation causes drastic changes.
If an equilibrium is stable on one side and unstable on the other, it is classified as semi-stable.
