A Cyborg (サイボーグ, Saibōgu) is a cybernetically enhanced living being.
The main difference between a cyborg and a robot is that a cyborg is partially organic and living, while a robot is completely inorganic. Both humans and animals can become cyborgs, by having either cybernetic parts implemented in their body, or having organic parts replaced with cybernetic ones.
There are underground matches known as "Cyborg Fights", where cyborgs fight and people bet large sums of money. The cyborgs in these fights would usually only have modified, wrists, legs, and eyes. There was one cyborg, Solitude, who was unbeatable, so since no one would bet any money on him, he was kicked out.
According to Solitude, most humans are modified by only 30%. Modifying the body by more than 60% is extremely risky and the chances of success are extremely slim.