As much as we can taste, smell, touch, hear and see the world around us; all sensations arrive at the brain along a nerve fibre.
Signals that arrive at the brain are all alike in so much as they are a nerve impulse.
There is no functional difference between a nerve impulse from taste or from sight as it enters the brain. All nerve impulses are functionally the same.
Our brain only ever receives nerve impulses.
The only way our brain can distinguish between one nerve impulse and another is their relative position. There is no special labelling, no side carrier that specifies the type of information carried. A nerve is a nerve is a nerve at the point it arrives at the brain.
The brain takes in just one type of signal and yet is able to interpret that one type of signal into all the different sensations we experience.
So... given that the brain only receives one type of signal, how does it create such a rich and varied sensorium?
The only information the brain has beyond the existence of a nerve signal, is the relationship of that nerve signal with all the other possible nerve signals.
Think of a single pixel on a display screen. That single pixel has no inherent significance by itself. However, when considered in relation to all the other pixels on the display screen, that pixel displays a picture, a movie, a game, a spreadsheet, the time in London, Tokyo and New York and everything else we can display on a screen.
Likewise, a single nerve impulse tells us very little. But in conjunction with other nerve impulses tells us a spider is crawling across our skin, or the roller-coaster is plunging to certain doom.
We use the relationships between nerve impulses to construct/re-construct the relationships that lead to those nerve impulses. Taste, touch, sound, sight and smell are "just" different sets of relationships.