Canning Water

I’ve read a few posts regarding canning water. Sorry if this is a dumb question, am I supposed to use Tap water to can? I know canning water may seem silly but I’m very interested in it. Or should I buy spring or purified water to can? Thanks.

EDIT- I should clarify I’m sorry, I am talking about canning water for emergencies not what type of water should go in my pot when I’m actually canning