The umbrella term for every technique used to record the real, physical condition of a site or building digitally: laser scanning that produces a point cloud, drone photography, 360-degree photo documentation, and photogrammetry (building 3D geometry from overlapping photographs instead of a laser). Scan to BIM is the specific workflow of turning reality capture data into a usable Revit model - reality capture is the broader category that workflow belongs to.

On a renovation project, good reality capture at the start is what makes an accurate as built model possible later; skipping it usually means a model built on guesswork and old, unreliable drawings instead.