A yoga board provides a bit of instability with the use of rockers under the board. The instability causes your core muscles to engage a bit more than if you were on a flat surface.
For those experience in yoga, the yoga board is designed to take you to another level of yoga with the unstable environment. It causes you to focus on your moves and what muscles are being engage.
For the beginner, a yoga board adds a fun dimension to any workout.
For the surfer, stand up paddle boarder or snowboarder....