Then I’m guessing you haven’t seen many engines in general then
It’s an intercooler, most turbo/supercharged engines have them.
cools the incoming compressed air so that it’s cooler.
There have been experiments over the years that use the car’s HVAC system to cool the air further, some vehicles (newer BMW M cars for example) has a system that sprays the intercooler with water to get an evaporation cooling effect, which allows for more aggressive ECU tuning.
They are only practical in vehicles with forced induction as the air is being effectively heated by the turbo/supercharger. The air gets hotter due to being compressed. On N/A engines, this doesn’t happen.