Where is there life in the desert?

Depending upon the type of desert, there are myriad forms of life, from microscopic organisms to 60-foot-tall saguaro cacti. Deserts can look very different from one another. In the deserts of the southwestern part of the United States, evidence of life is abundant both in the plants native to the region, such as the saguaro cactus, and in the animals that live there, such as scorpions, Gila monsters, and rattlesnakes, as well as various species of birds, like the cactus wren, roadrunner, and burrowing owl. In the massive Sahara desert of northern Africa, there are many types of animals, including camels, hyenas, snakes, jackals, and crocodiles. The "Empty Quarter" region of the Arabian Peninsula is the most difficult desert region in which to find life forms, but they have existed there and include gazelle and the Arabian oryx. 
While images of the Empty Quarter tend to consist solely of sand dunes, there is plant life there, with the various types of plants having Arabic names, such as Az-Zahar and Al-Alqa. Obviously, these are plants that can exist on minimal water, as in the other deserts discussed.
In short, even the most arid regions on Earth have forms of life, including plants and large animals. Because the word "life" encompasses all living organisms, there is some form of life virtually everywhere on the planet.