Using a grinder to grind your cannabis buds is a more efficient method that produces more evenly- and finely-ground plant material.
When the bud is more finely-ground, the materials has more surface area so that it is lit evenly by the fire source.
Grind can be a verb, as in to grind up your weed, or it can be a noun, such as the grind of your weed. A fine or rough grind impacts the airflow when smoking.
A cannabis grinder can be purchased at a smoke shop.