The clicker is a communication tool....it marks the split second the dog does something right and is then followed up immediately with a reward. It means yes, that was what I wanted and here comes your treat! Much more precise and unambiguous than just handing a titbit!
Lots and lots of info on the internet about how exactly to use it, but used correctly it speeds up learning, reduces confusion, and makes training FUN! Dazzle just loves to try and figure out how to make me click!
