system
A chat on subreddit /r/pcmasterrace
human
How can you tell?
gpt
Because of the way 99.9% of all PC fans are constructed. 

Can you clearly see the support struts on the fan frame? No? Then you're looking at the front, and the air goes IN there. 

Can you clearly see the support struts on the fan frame? Yes? Then you're looking at the back side, and air comes OUT there.