Lets talk tree-surgeon lingo
Pollarding is a method of pruning that keeps trees and shrubs smaller than they would naturally grow. It is normally started once a tree or shrub reaches a certain height, and annual pollarding will restrict the plant to that height.
Crown Reduction. The reduction in height and/or spread of the crown (the foliage bearing portions) of a tree. Crown reduction may be used to reduce mechanical stress on individual branches or the whole tree, make the tree more suited to its immediate environment or to reduce the effects of shading and light loss, etc.
Tree crown lifting involves the removal of lower branches with the end result being to lift the height of the base of the crown. This may be carried out to increase the clearance between the ground and the lower branches in order to: Allow for access below the tree, particularly vehicles. (In the UK, highways regulations state that the clearance over a highway must be 5.2 meters and 2.5 meters over a footway) To help improve light levels Aesthetically enhance the tree by creating a balanced lower crown Remove interference with structures or property such s fences, telephone lines etc