A: Reward-based training uses ‘rewards’ for doing the correct behavior. A ‘reward’ is anything that the dog wants at that moment. Food is just one of many rewards that a dog could want. It’s easier for us to use food in training because it usually motivates every dog and is transportable! But at home, you can use all kinds of things as rewards: giving his dinner, throwing the tennis ball, going for a walk, etc., as long as the dog thinks it’s rewarding!
As for praise, dog’s generally don’t work for praise. (People may work for praise for a short time, but eventually you will want a paycheck! Let me ask you how you would feel if you just got a pat on the back at work instead of a paycheck?!) People work for money and dogs work for food!