Pay As You Go (PAYG) means you don't have to buy a ticket when you catch the bus. Just tap on and off and we'll charge you the right amount. When you buy a ticket from the driver and pay with contactless, you're given an actual ticket ,that is valid for travel over a fixed period of time or number of journeys.
Right now, PAYG is only available for adult tickets. But you can still pay for most other tickets using a contactless card on the bus.