What key metric, related to motion through space, differentiates the Laniakea definition from the older Virgo Supercluster definition?

The velocity field

The transition from viewing our locale primarily as the Virgo Supercluster to recognizing the Laniakea Supercluster involved a fundamental shift in methodology. The Virgo Supercluster definition historically relied more on static proximity or general gravitational influence at a specific cosmic time. In contrast, the modern definition of Laniakea heavily incorporates the velocity field—the actual movement or vector of motion of the galaxies through space. By mapping how matter flows, Laniakea groups together everything that shares a common trajectory toward the Great Attractor, making it a dynamic entity shaped by continuous motion rather than just a snapshot of gravitational clustering.