Generational Grouping
From The SpiritWiki
A Generational Grouping is a grouping of children with specific vibratory frequencies, and specific potentials of Consciousness, that incarnate in temporal (and sometimes physical) proximity. The Baby Boom that occurred mid-20th century is the most obvious example of a Generational Grouping, but groupings occur all the time.
Generational Groupings may be referred to by the specific frequencies they bring with them, for example Indigo Children, Violet Children, Crystal Children, and so on.