What is the difference between a tolerance/dependence and an addiction?

Three things: You have mentioned three different things: tolerance - needing more of a drug to get the same effect. Very common in many drugs. Dependence - a physical/psychological need for a drug, often accompanied by specific symptoms if you stop taking it. Addiction - pattern of [harmful] behaviors involving a substance or behavior; typically involves dependence/tolerance related to the substance/behavior.

Semantics: Tolerance is a normal consequence of repeated exposure to a drug. It can be accelerated by exposure to high, intermittent levels. Tolerance is not the same as addiction where there is a abnormal dependence upon a substance associated with adverse consequences-be it legal, behavioral or otherwise. Dependence may or may not be an adverse situation based upon a number of factors such as preoccupation.