The book addresses the main processes of cellular and molecular physiology in living organisms. It serves to create a bridge between biophysics and cellular and molecular biology, in which the determining factor is time. This approach will enhance the understanding of biophysics for students of medicine, biology, physics and engineering, among others. Thanks to the progress of scientific and technological research, the biological sciences have become quantitative. From an analogue description of the properties of living organisms, we have now moved to their spatio-temporal quantification, with the understanding that all natural processes are digital events. The dynamic processes at the heart of cellular excitability, muscle contraction, through to the perception of the surrounding environment, are based on probabilistic events that, today, are not only interpretable, but potentially predictable. The book contributes to this ongoing revolution in biology by drawing more and more young people into this fascinating world.