The nose is closely related to taste. The nasal cavitity will al of its receptors and tiny blood vessels and sensitive hairs extend almost all the way to the brain. There is a thin layer that separates the two. The taste buds are located on the tongue. They too are very sensitive. The nose with all its sensory mechanisms and the tongue with all of its work together and travel up to the brain where a decision is made by the brain as to what command it will give. Does it like the food being tasted? Is the scent it is picking up on one that might ideicate a delicious food or perhaps it's cow poop.
The brain distinguishes but not all brains distinguish scents and smells alike just as they don't process many things alike. One person may like the smell of hay while it reminds another of the back breaking work they were made to do as a child. One person might love fish and the smell of fish makes them hungry while it makes another individual sick to their stomoch. Scents and tastes work together once their signals reach the brain but how everyone processes them is different.