Free will (sacchanda) is the ability of the individual to freely choose, without any extraneous influences, what course of action he or she will take.
The idea of free will is usually contrasted with determinism. Buddhism does not teach that we have complete freedom or that we are determined, but that our will is conditioned or limited to a greater or lesser extent. Introspection will reveal to us that our ability to choose and act is often under the influence of and thus limited by our desires, our skill or lack of it, the power of circumstance, our health, the strength of our habits and convictions and numerous other factors. Psychology also tells us that our unconscious may subtly influence us without our knowledge.
The purpose of much Buddhist training is to see and understand the factors that condition us and then gradually overcome them. This way we become more free and make better choices.