Networks of coupled oscillators are observed in various domains of science. From physics to economy through biology, they are used to explain how collective behaviour emerges from interacting oscillators. In this book, we study through two specific examples, how biological systems use the distinctive properties of interconnected networks, widely studied in the biophysical science, to propagate informations and regulate vital physiological processes. Our interest focuses on: (1) Extension of the study of the communication via Ca2+ waves to a 1D and a 2D array of cells. (2) Communication through the quorum sensing phenomenon governing the transition from the saprophytes way of life to the infectious cycle for pathogenic bacteria particularly for Dickeya dadantii (Ex Erwinia Chrysanthemi) bacteria.