Deserts are typically found in regions with little rainfall, but they can also occur due to other factors. Here are some key points about desert formation:

1. Low precipitation: Most deserts are characterized by very low annual rainfall, usually less than 250 mm (10 inches) per year.

2. Rain shadow effect: Mountains can create rain shadows, causing deserts to form on the leeward side. As moist air rises over mountains, it cools and loses moisture on one side, resulting in dry conditions on the other.

3. Distance from oceans: Deserts can form far from oceans, where moist air currents have difficulty reaching them.

4. Atmospheric circulation patterns: High-pressure systems often prevent cloud formation, leading to clear skies and minimal precipitation.

5. Cold ocean currents: In coastal areas, cold ocean currents can prevent cloud formation, creating desert conditions.

6. Continental interiors: Far from the moderating influence of oceans, continental interiors often experience extreme temperatures and low precipitation.

7. Human impact: Overgrazing, deforestation, and irrigation practices can contribute to desertification in some regions.

So, to complete your statement: Deserts are found where there is little rainfall or where atmospheric and geographic conditions limit moisture availability.