Trunk:
The trunk of the tree is also the main body of the tree. It is what connects the roots to the ground and the branches to the canopy
Limb:
The tree limbs are any of the main branches coming from the trunk
Roots:
The roots go underground in most cases. Sometimes you can see them along the surface of the soil. Roots provide the minerals and water found in the ground for the trees growth. The roots are also considered the trees foundation and will grow with the tree to support its needs throughout its lifetime.
Drip Edge/Drip Line:
The drip edge is the area just outside the cover of the canopy. The area under the canopy is called the critical root zone and the area just outside that would be the feeder root zone. See Image
