Collective pitch?

I am a newcomer to radio controlled helicopters and I don't know what collective pitch is and what non collective pitch is. Can anyone help me out?

[Daz(DJLFlapper)]

Hi tp

Collective pitch is when the blades on your main rotor move to change the angle of attack when the throttle is applied.
Fixed pitch is when the blades do not move the angle of attack.

The advantages are that with fixed pitch (FP) blades you need not setup the Pitch through the throttle range,
Where with collective pitch (CP) heli's it is very important to know what your pitch is through the throttle range, usually 5+degrees at center stick.
An example of the CP range would be -2 at idole +5 at mid stick +9 at full throttle. giving -2+5+9 Pitch.