Definitions for "Saros Cycle"
The geometry of the Sun, Moon, and Earth very nearly repeats itself every 18 years. if you take the time of a solar eclipse and add 6585.32 days to it, you will have a good forecast for the occurence of another very similar eclipse. The most significant difference from one eclipse in a Saros cycle to the next is the location of the eclipse on the Earth.
An 18-year, 11-day repeating pattern of solar and lunar eclipses caused by a combination of the tilt of the lunar orbit with respect to the ecliptic and the precession of the plane of the moon's orbit.
A period of 18 years 11.3 days between eclipses with very similar alignment geometries (same time of year, same nodes).  The saros cycle = 223 synodic months = 242 draconic months = 239 anomalistic months.