A desert receives less than 10 inches (250 mm) of precipitation per year on average. A semi-arid region usually receives between 10 and 20 inches (500 mm) of precipitation per year on average and are frequently grasslands.
the main difference between a hot and cold desert is the animals
Hot deserts are usually sandy. Cold deserts are usually rocky
The main difference between a hot and cold desert is the difference of temperature. The Mojave Desert in California and the Sahara Desert in Africa are examples of hot deserts, where temperatures can soar above 110 degrees Fahrenheit. The continent of Antarctica and the Gobi Desert in China are examples of cold deserts, where temperatures can go below 30 degrees Fahrenheit.
Most hot deserts have a mild winter. Cold deserts may be quite hot in the summer but winter temperatures can plunge to well below zero. Some cold deserts (Antarctica, Patagonia, Atacama) are quite cold or cool the year around.
The two main deserts I assume you are talking about is hot and cold deserts. The difference between them is temperature (warm moderate summers for hot deserts, low rainfall.) Cold deserts may have snowfall and much lower temperatures in the winter. Summers in cold deserts may get quite hot, however.
reptiles mostly live in hot semi arid areas or deserts near a permanent water sauce
Deserts are arid, nor semi-arid. Therefore, your question is invalid. Semi-arid regions are usually grasslands or steppes.
Deserts are hot during the day, when the sun is shining. Once the sun goes down, then the temperature drops. This is because desert surfaces receive a little more than twice the solar radiation received by humid regions and lose almost twice as much heat at night.
Hot deserts are very hot in the summer but have mild temperatures in the winter. Some cold deserts are cool or even cold all year long. Others are hot in the summer but can be bitterly cold in the winter.
There are hot deserts, such as the Sahara, Mojave and Kalahari and there are cold deserts such as Antarctica, the Gobi and the Patagonian Deserts.
Not all deserts are hot. There are also polar deserts, cold winter deserts as well as cool coastal deserts.
There are two major classes of deserts:Hot Deserts such as the Sahara, the Arabian Desert and the Mojave Desert.Cold Deserts such as Antarctica, the Gobi Desert and the Patagonian Desert.