WHAT IS IT
The process of placing weights on your wheel rim using specialized equipment to ensure each of your wheels is balanced. Wheel balance refers to the proper distribution of weight around a revolving tire and wheel assembly.
WHY DO IT
Balancing greatly minimizes the "wobble" effect which causes your steering wheel to vibrate typically at high speeds. Continued vibration will eventually cause wear and premature replacement of your tires, suspension, alignment and steering components.
WHEN TO DO IT
When you (i) rotate your tires (ii) purchase new tires (iii) experience steering wheel vibrations.