A cyborg (cybernetic organism) is an organic creature of which synthetic enhancements/upgrades have been integrated into their bodies for the purpose of improving physical and/or mental capacities, although it is also used for replacing lost limbs and recovering from serious injuries as well.
As part of their 314 Project, Initiative scientists Maggie Walsh and Francis Angleman designed special bio-mechanical demonoids, creatures combining the advancement of technology, the superior strength and emotional detachment of demons, and the intelligence and adaptability of humans into one being. Adam went rogue and killed his creators soon after being completed, and later performed a similar process on Forrest Gates after killing him. Both were slain by the Scooby Gang.
Shortly after taking over Wolfram & Hart's Los Angeles branch, Team Angel ran afoul of a mysterious organization of cyborg ninjas, who intended to use a mystical artifact to strip Angel of his free will and make him their slave.