Tinder is the smallest. Tinder ignites into flame with the
smallest spark. Types of tinder include: cotton balls. dry
grass, Cattail fluff, and Birch tree bark.
Kindling is slightly larger. It refers to any ignitable material
that is larger than tinder, but smaller than firewood
(fuelwood). Most people use small sticks, cedar bark, and dry
leaves for kindling, which ignite more quickly than the firewood
and burn for longer than the tinder.