Could you explain the difference between active lung disease & lung injury?

Ongoing damage: Active lung disease refers to a process that is not under control and can lead to ongoing damage or injury to the lung. Lung injury when acute is a one time event, but when chronic is likely caused by that active lung disease.

Different entities: Lung injury is a non-specific term that refers to any form of injury to the lung caused by trauma, infection, inflammation etc. Active lung disease again is a non-specific term for chronic disorders of the lung that can flare up from time to time and become "active". So this so-called active lung disease in someone with a pre-existing lung disease may be caused by an additional injury to the lung.