Core energy is the 'life force' that separates living being and machines. It is the source of consciousness and the ability to reproduce other lifeforms above and beyond their constituent components. Much is not known of the exact nature of core energy, but the Alterra and others have amassed great 'experience' with it. They have garnered the ability to transmit it from one body to another, whether that 'body' be biological or technological in nature, as have the Asgard, who routinely transmit their core energy into their ship's computer system to circumvent the 'death' of their fragile bodies in emergency situations.
This method of core energy transfer is also how the Asgard, as well as Remus, transfer themselves into new clone bodies.
AscensionEditAscension is another transfer process of one's core energy, but instead of moving from one 'body' to another, one's core energy is translated into an energy matrix formed from the biomatter conversion of the original body...essentially the core energy is briefly liberated from physical existence then bound to an energy-based matrix.
A similar process occurs in the reverse when an ascended being 'descends.'