Attunement is an arcane art that allows practitioners to affect their environment or to enhance themselves either physically or mentally.
Those trained in attunement are called attunweiyld. Attunweiylds use a mental technique that allows them to directly channel naturally occuring flows of weiyld through their bodies. Once 'attuned' the weiyld can be channeled into a variety of effects that include increasing strength, throwing lightning bolts or glimpsing the future to name a few.
An attunweiyld uses the memories and feelings surrounding personal experience to attune. Since each of the nine suns produces its own variety of weiyld, different memories and experiences are required to attune each one. Personality and life experience both help to determine which suns any given attunweiyld can attune to. Few can attune all of them. Knowing about an attunweiyld's personality can give a good idea as to which abilities he or she is likely to use.
Anyone can learn to attune, if they are willing to take the time to do so. Training is difficult and many quit before finishing.