The difference is that a “ Tree Guy “ may posses knowledge and experience… And a CT licensed arborist has been tested and proven to have knowledge and experience by the state of Connecticut DEEP. Arborists are required to maintain this license with continuing education in the form of credits. This testing and CT law is unique to our state and has been in effect for over 100 years in order to protect our trees and land values. I would describe this test as a 4 part, 6 month bar exam for industry leaders.