"Which" is a word that helps you choose between two or more options. It's like when someone asks you if you want chocolate or vanilla ice cream, but you're not sure which one to pick. You could say "which one is your favorite?" to someone who knows a lot about ice cream and can give you advice.
"Which" is very helpful when you're trying to decide between things, like which book to read next, which toy to play with, or which flavor of candy to try. You can use "which" in a sentence and then list your options, like "which color do you want, red or blue?"
When you use "which," you usually have to make a decision based on the answers you get. So if someone asks you "which animal do you like better, dogs or cats?" and you say "dogs," then you have made a decision!
So, "which" is a word that helps you choose between two or more things, and it's really useful when you want to make a decision.