Tissue rearrangements that are essential for several physiological and pathological conditions depend on the coordinated migration of cellular clusters. The success of these clusters in reaching their target tissues relies on their ability to migrate in a synchronized manner. An outstanding feature of collectively migrating cells is their high degree of migratory efficiency. A large body of evidence shows that this property emerges from fine-tuning the mechanical coupling between neighbor cells, which in turn synchronizes both fluent molecular communication and efficient synchronization of cytoskeletal activities of collectively migrating cells. This exquisite communication ensures efficient transmission of signals from the microenvironment and across the cluster. This highly regulated, cooperative, and peculiar mode of cellular motion is defined as collective cell migration (CCM) and due to its relevance for embryogenesis, wound healing, regeneration, and cancer metastasis, CCM is currently a research hotspot.