Description of reverb effects for guitar

Reverb, or "Reverberation", is a guitar effect that is based on the sonic properties of sound waves, and whether they are absorbed or reflected off of adjacent surfaces. For example, rooms that have "soft surfaces" tend to absorb sound waves and thus any sound heard after the original one is usually less audible. In other words, you don't hear reverb, or "echo", because the sound barely bounces back to you. This is the prime reason you see recording studios with the foam on the walls. Managing this natural phenomena is crucial when trying to minimize bleeding with acoustic microphones. Having said that, it stands to reason that hard surfaces promote reverberation. The proximity of the hard surface also plays a huge role. Think about playing your guitar amp in a gymnasium vs. a 10' x 10' bedroom. Of course, the gymnasium will have much more reverb vs. the bedroom. To a sound engineer, the gymnasium would be "wetter" than the bedroom. Reverb, like delay, is sometimes referred to as a time based effect due to the aforementioned principles.