1. A wave passes through a substance
2. Refraction is a type of transmission
3. Transmission is the more general term for a wave appearing on the opposite side of a boundary (the opposite of reflection)
4. Refraction is specifically the change in direction of a wave when it crosses a boundary between two materials that have a different density
5. When passing through a material, waves can be partially absorbed
6. The transmitted wave will have a lower amplitude if some absorption has occurred
7. During transmission, the frequency or speed of the wave does not change
8. Reflection, refraction, and transmission occur for all types of waves, both transverse and longitudinal