A balance bike is a bike without pedals. While it has a frame, fork, handlebars, wheels etc, it has no drivetrain. To move forwards, kids push off the ground with their feet, like Fred Flintstone. Another thing balance bikes don't have is stabilizers (A.K.A. training wheels). Since kids have their feet on the ground, they can develop their balance and coordination as they are not supported by stabilizers. This allows kids to develop their balance first, before progressing to pedals.