Let's take a quick break from imaginary exponentials, and talk about systems.
There are several ways describe systems. When a system is in equilibrium, it is said to be relatively static. Things have stabilized, and are basically in steady state.
These systems are typically described using linear models.
When a system is in flux, and changing, we typically describe them as being dynamic. We may not know where they will end up, but can describe them based on how they change.
