Refer to figure.
To turn the main rotor the engine must exert a turning force or “torque” on the main rotor shaft.

According to the Newton’s 3rd Law:

• Every action must have an equal and opposite reaction. So, the effect of applying torque to the main rotor shaft, is an equal and opposite rotation of the fuselage.

Conventional helicopters use a tail rotor and some others, the NOTARs, a variable pitch fan at the front of the tail boom, to counterbalance the torque reaction through the anti-torque or yaw pedals, producing a horizontal tail rotor thrust.

The tail rotor thrust is altered (increased/decreased) by changing the pitch angle of the tail rotor blades through the yaw or anti-torque pedals.

For a counter-clockwise helicopter, the horizontal tail rotor thrust is to the right, to counteract the torque effect.

If a wind comes from the right, then the induced flow and velocity of the tail rotor will increase, the AoA will decrease and as a result the tail rotor becomes aerodynamically more effective.