In Lurianic Kabbalah, the vessels formed to hold the divine light could not contain it and broke. Sparks of holiness fell and were trapped in husks, mixed with the forces of evil. The whole of history, and every human act, is part of gathering the sparks and repairing the break.
Shevirat ha-kelim
The breaking of the vessels: the Lurianic catastrophe in which the vessels of divine light shattered, scattering sparks.
Also: breaking of the vessels