In this lesson, the focus is on the climatic characteristics of tropical deserts, which are regions with high temperatures throughout the year and experience very low rainfall, typically less than 250 millimeters annually. These deserts are primarily located on the west coasts of continents between 5 and 30 degrees north and south of the equator, including areas such as the Sahara Desert in Africa, the Arabian Desert in Asia, and the Atacama Desert in South America. The lesson also discusses how coastal desert areas tend to be cooler due to cold ocean currents, while inland areas can experience temperatures as high as 50 degrees Celsius.