What is the difference between a Tree Lopper and an Arborist?

http://goldcoasttreeserviceblog.bravesites.com/entries/general/surprising-facts-you-may-not-know-about-the-difference-between-a-tree-lopper-and-an-arborist

One of the most pressing needs after having a thunderstorm is to have the branches and leaves of the trees in a compound trimmed. Here a differentiation needs to be made involving the Arborist and the tree lopper