Lenz's Law states that **the direction of an induced current** (or electromotive force, EMF) **in a conductor will always oppose the change in magnetic flux** that caused it.
In simpler terms: if a changing magnetic field induces a current in a circuit, the induced current will generate its own magnetic field in such a way that it resists the change in the original magnetic field. This is a consequence of the law of conservation of energy.
For example, if a magnetic field through a loop is increasing, the induced current will flow in a direction that creates a magnetic field opposing this increase. If the magnetic field is decreasing, the induced current will try to maintain it by creating a field in the same direction as the original.