From Wikimon

Realization (リアリゼーション Riarizeeshon) is a term for when a Digimon enters the Real World from the Digital World. (Dub: Bio-Emerging, Realization).

In Digimon Tamers, a digital field surrounded by thick fog is created when one realizes. In the Dub, it is referred to as "Bio-Emerging" . It is the opposite of metaphorize.

In Digimon Savers it is the same, yet partner Digimon can also Realize from storage space inside the Digivice iC.