What is the difference between en route and airway? I am studying about airway now. But there are multiple terms that mean airway like enroute or air route. I don't know exactly what the difference is between them.

Airway, en route, air route, air path

I want to know the difference of meanings or definitions between above terms. Please tell me in detail.
Enroute: An aircraft that is on its way to its destination.

Air Route: A specific route that an aircraft takes, just like a car route, taking specific highways and roads to get to your destination. Planes do not go a straight line from their origin to destination.

Airway: A highway in the sky. That is what planes fly in their route. So for example 2 planes flying the V23 Airway would have them flying the same path on the airway specifically.