  We introduce an active version of the recently proposed finite Voronoi model
of epithelial tissue. The resultant Active Finite Voronoi (AFV) model enables
the study of both confluent and non-confluent geometries and transitions
between them, in the presence of active cells. Our study identifies six
distinct phases, characterized by aggregation-segregation, dynamical
jamming-unjamming, and epithelial-mesenchymal transitions (EMT), thereby
extending the behavior beyond that observed in previously studied vertex-based
models. The AFV model with rich phase diagram provides a cohesive framework
that unifies the well-observed progression to collective motility via unjamming
with the intricate dynamics enabled by EMT. This approach should prove useful
for challenges in developmental biology systems as well as the complex context
of cancer metastasis. The simulation code is also provided at
https://github.com/jxhuangphys/Active_Finite_Voronoi_simulation.
