ELI5: Explain Like I'm 5

Che!

Che is actually not a topic, it is a word that means "hey" or "dude" in Spanish. People use it to get someone's attention or to refer to someone informally. It's like saying "hey buddy" to your friend when you want to talk to them. So, next time you hear someone say "che", you'll know that they are trying to get someone's attention or just being friendly.