An Oblivion Continuum was Dalek technology. It involved the containment of wormholes for power sources. They could be used to power androids or as explosive warheads, or both. An Oblivion Continuum was powerful enough to shatter planets and cause worlds to bleed into the next dimension. Whilst the Doctor was aware of the existence of such power sources, he had never seen one up close and had little idea of how to disarm them if the Daleks set them to explode.
A trio of Dalek survivors of an encounter with the Doctor created the android Edwin Bracewell to ensure their masquerade as human weapons in the Ironside Project during World War II. They implanted an Oblivion Continuum in him as both an energy source and a bomb to destroy the Earth once their mission was complete. After the activation of the Progenitor device and the creation of the New Dalek Paradigm, the Dalek Supreme told the Eleventh Doctor an Oblivion Continuum was in Bracewell. Unless he called off his attack, they would activate the power source and destroy the planet. When the Doctor complied, the Daleks activated the bomb anyway and fled through a time corridor. The Doctor only managed to stop the Oblivion Continuum from detonating with the aid of Amy Pond, giving Bracewell a reason to live, deactivating the weapon. (TV: Victory of the Daleks)