A syzygy is when three or more celestial bodies align themselves in a 18o degree, straight line orientation, where they all lie along the same path.  This is usually mentioned in connection with alignments of the sun, the Earth, and the moon.  When these alignments happen, they set the stage for an eclipse of some sort.  An eclipse is where one celestial body falls into the shadow of another celestial body.  A lunar eclipse is the most common, occuring when the moon passes within the Earths shadow.  A solar eclipse is less common, occuring when a portion of the Earth is covered by the moons shadow as it passes between the Earth and the sun.  There can be a maximum of seven eclipses per year in an eclipse cycle, such as the Saros cycle.  2011 was the last year with the maximum number of seven eclipses, 2038 will be the next year with the maximum number of eclipses.  There will be years in between those two with minimal numbers of eclipses.