What does it mean to bit-up a horse?

"Bit-up" refers to the process of adjusting a horse's bit or bridle to ensure a proper fit and comfort for the horse while riding. This involves checking that the bit is positioned correctly in the horse’s mouth and that the bridle is snug but not too tight, allowing for effective communication between the rider and the horse. Proper bit-up techniques help enhance control, performance, and the overall well-being of the horse during riding.