Acoustics

Indoor acoustics
Indoor acoustics is the acoustics properties of indoors. Indoors, as opposed to outdoor acoustics generally have a lot of reverberation. This is because walls and ceilings are flat, causing sound waves to bounce off of them. You may find that rooms with lots of furniture have much less reverberation. This is because sound is absorbed by furniture.

Sometimes certain objects vibrate, because their resonant frequency is reached. If a frequency is emit from a source that matches the resonant frequency of an object, the object will vibrate and produce sound at the same frequency, making certain frequencies louder.

Outdoor acoustics
Outdoor acoustics are slightly different. You may get a little reverberation from floor reflection, however in open areas, dealing with external factors of sound is usually not so much of an issue. The main factor is wind, and other ambient noise. In a soundproof room, this wouldn't be a problem, but outside you will need to deal with birds, people and wind. To record outside, use a pop shield in order to prevent the sound level from clipping, and a wind shield in order to pick up less wind.

Simulated acoustics
Acoustic properties can be applied via computers. Reverb can be applied to samples artificially, along with the effects of resonance.