The 2004 Nobel Prize in Physiology or Medicine was awarded to Richard Axel and Linda Buck for their discoveries related to the olfactory system. They identified how the sense of smell works by mapping the genes responsible for odorant receptors, which are crucial for detecting different scents. Their research revealed that the human nose can distinguish thousands of odors through a complex system of receptor proteins. This groundbreaking work has enhanced our understanding of sensory perception and has implications for various fields, including neuroscience and psychology.