"While We Sleep" refers to the various processes that occur in the body and brain during sleep. Sleep is essential for physical health, cognitive function, and emotional well-being. During this time, the body repairs tissues, builds bone and muscle, and strengthens the immune system. The brain also processes information, consolidates memories, and clears out toxins. There are different stages of sleep, including REM (Rapid Eye Movement) and non-REM sleep. Each stage plays a crucial role in overall health. REM sleep is particularly important for learning and memory, while non-REM sleep helps with physical restoration and growth.