Bribery is when we give someone something so that they do something for us. Would you say that your employer uses bribery on you to go to work every day because they pay you for doing what needs to be done? Of course not. Similarly, when you reward your child for learning and practicing good behavior, it is not a bribe.
An example of bribery in parenting would be if you tell your child they can have dessert if they bring you the remote control for the TV. In this situation your motive is selfish (you want something for yourself) and your goal is not to teach your child.