Nanotechnology, often shortened to nanotech, is a term referring to any technology that manipulates matter on an extremely small scale. 

Uses and Applications

The Ousters contain nanotech within their bodies that allows them to physiologically adapt to new environments within a short span of generations, accelerating the process of evolution.

Aenea's body contains nanotech that allows her to freecast, and which can be spread like a virus to other people.

The Cruciform symbiote can be considered a form of nanotechnology, as it manipulates the individual atoms of its host to revive and reconfigure them after death.