The upgrading of humans may follow any of three paths: biological engineering, human-machine engineering, and the engineering of non-organic beings.
Biological engineering starts with the insight that we are far from realizing the full potential of organic bodies in the present day. Bionic engineering will go a step further, merging the organic body with non-organic devices such as bionic hands, artificial eyes, or millions of nano-robots that will navigate our bloodstream, diagnose problems, and repair damage. Such bionics could enjoy abilities far beyond those of any organic body.
Today, humans improve machines; in the future, machines will improve machines, potentially much faster than humans could have done—which is the fascinating and controversial idea of singularity.