Sidereal vs Synodic Month

The time it takes for the Moon to orbit the Earth relative to the "fixed" stars is called a Sidereal Month. A Sidereal Month is about 27.3 days.The time it takes for the Moon to cycle through one set of phases of illumination (one lunation) is called a Synodic Month, or just a regular Month.The time difference between a Sidereal and Synodic Month is due to the advancement of the Earth in its orbit around the Sun during a Sidereal Month. The Moon must travel not 360 degrees, but about 390 degrees, in order for it to realign itself relative to the Sun, say New Moon to New Moon.