Many so called tree guys or "arborists" do not properly prune. Improper pruning can cause branch failure, rot, excessive sprouting, and stuctual defects. Tree of Knowledge does their pruning according to ISA standards and ANSI standards.
TYpes of pruning-
dRop Crotch pruning: reducing the canopy size and branch weight by pruning longer/heavier branches back to shorter stronger limbs at least 1/3 of the size of the main.
Thinning: Selectively removing certain branches that may be weak. Opening up the crown of the tree to reduce wind resistance.
cleaning: removing dead branches usually greater than 1" diameter.
topping/heading: not usually recommended. cutting the tops back of the main trunk or individual branches to reduce the height/width of the tree. unlike drop crotching branches, topping cuts back to any point on the stem.
lions tailing: never recommended. thinning out all the interior branches and pushing the weight out farther towards the ends of the branches causing more stress and branch failure.