Alright kiddo, so no-fi is short for "no-fidelity" which means that something isn't super clear or high quality like you might have with music or movies.
You know how sometimes you might listen to a song on the radio and the sound isn't super clear, like it's really fuzzy, or you might watch a video and it's really blurry? Those are examples of no-fi!
Sometimes people purposely make things no-fi because it makes them sound or look cool (kind of like how some people like that old-timey vinyl sound when listening to music). Other times, it might just be the best you can get with the equipment you have.
So remember, no-fi isn't always what you want, but sometimes it can be cool and make things sound or look different!