The human nose is quite a unique organ in the animal kingdom, a prominent facial bulge only surpassed by the long-nosed monkey. As we learned in the previous chapter, it is essential for breathing, where the mucosa of the small nasal cavity humidifies and heats the air before allowing it to enter the lungs. A part of the air flow is guided to the upper part of the nasal cavity, where it allows for small odorant molecules to activate smell receptors. This allows for us to register smells in our surroundings during inhalation and food aromas during expiration or swallowing. With an array of around 380 different types of smell receptors, we are able to distinguish millions of different smells. Upon activation of these smell receptors, the signal is within milliseconds transformed to an odor in our brain. This chapter outlines the processes behind this registration, how it is continuously replaced, and the mechanisms required to maintain the fine balance in the nose that ensures our ability to breathe and smell through this remarkable little organ.