Define or discuss order of differential equation?

The order of a differential equation refers to the highest derivative that appears in the equation. For example, in the equation ( \frac{d^2y}{dx^2} + 3\frac{dy}{dx} + 2y = 0 ), the highest derivative is ( \frac{d^2y}{dx^2} ), indicating that it is a second-order differential equation. The order provides insight into the complexity of the equation and the number of initial conditions needed for a unique solution.