What's the difference between the terms sound insulation and sound absorption?

Question

I would appreciate a couple of short, consice sentences to explain this difference if anyone can help me!

MANY THANKS

Answer 1

The second is one of the means to achieve the first. To insulate a room from sound, you might line the walls with a material that absorbs sound. To insulate an urban area from the sound of a motorway that passes through it, they might put up walls that reflect the sound upwards, making reflection another one of the means to achieve insulation.

Answer 2

Sound insulation refers to materials or methods of preventing sound transmission into or out of an area. Sound absorption means to absorb sound so that it is neither reflected nor transmitted. Sound absorption is often used in sound insulation, but it is also used for other purposes, such as tuning the acoustics of a room. Sound insulation can use techniques other than absorption; for example, reflecting sound away from the area being protected.