'There' refers to the location(s) that the card occupies. For most cards, such as minions and artifacts, that means one location. For example, Backstab's use of 'there' means the adjacent location of the tapped minion. For auras, that usually means 4 locations, most commonly the surface of 4 sites. For sites, 'there' includes both the site's surface location and it's subsurface location. For example, Upwelling will return subsurface minions and artifacts as well as those on the surface. 'There' is analogous to 'here.'