Do ECM motors use capacitors?

ECM Motors = Energy savings and added functionality PSC motors, or permanent split capacitor, use non-polarized capacitors and brushes to deliver electricity to the rotating parts. These brushes are known to wear out over time. ECM motors do not use brushes, thereby reducing maintenance and extending service life. DC motor types include ECMs. Is that correct? When used in air control systems,PSC motor are somewhat inefficient. The noise of the motor requires it to run at less than full load.