| Term | Definition |
| air | a mixture of nitrogen, oxygen, and minute amounts of other gases that surrounds the earth and forms its atmosphere. |
| water | a special form or variety of this liquid, as rain. (H20) |
| soil | the portion of the earth's surface consisting of disintegrated rock and humus. |
| rain shadows | a region in the lee of mountains that receives less rainfall than the region windward of the mountains. |
| light | something that makes things visible or affords illumination |
| temperature | a measure of the warmth or coldness of an object or substance with reference to some standard value. The temperature of two systems is the same when the systems are in thermal equilibrium. |
| elevation | the height to which something is elevated or to which it rises |
| wind | air in natural motion, as that moving horizontally at any velocity along the earth's surface |
| climate | average weather conditions of an area over time, including wind, temperature, and rainfall or other types of precipitaion. |