Power is based on knowledge and makes use of knowledge; on the other hand, power reproduces knowledge by shaping it in accordance with its anonymous intentions. Power (re-) creates its own fields of exercise through knowledge.

Foucault incorporates this inevitable mutual inherence in his neologism power-knowledge, the most important part of which is the hyphen that links the two aspects of the integrated concept together.

It is helpful noting that Foucault has a textual understanding of both power and knowledge. Both power and knowledge are to be seen as de-centralised, relativistic, ubiquitous, and unstable (dynamic) systemic phenomena. Thus Foucaultís concept of power draws on micro-relations without falling into reductionism because it does not neglect, but emphasizes, the systemic (or structural) aspect of the phenomenon.

However, he does not actually define knowledge.