Our nose gives us the sense of smell. We also breathe through our nose. Our nose can tell many smells apart: flowers, soap, fresh bread, and fruit smell nice. Rubbish, smoke, and rotten food smell bad.
Smells give us information. A nice smell from the kitchen tells us dinner is ready. A burning smell warns us of danger. A bad smell from food tells us not to eat it.
Example: Close your eyes. Let a friend hold a lemon, then a flower, then soap near your nose. Guess each one. Your nose is a smart detective!