Physiology, from the Greek (physis -nature, and logos -knowledge), is the science that studies the functions performed by living beings and their organs. The vine, as a living being, has an anatomy and organs. In order to live it needs to carry out processes such as translocation, photosynthesis, respiration and transpiration. The correct development of these processes has a direct impact on the quality of the grapes and, consequently, on the quality of the wine obtained from them. Understanding its life cycle and behaviour allows us to know the needs of the vine and, above all, how to meet these needs. If appropriate cultivation techniques are applied, they will deliver, as a result, a fruit of the best quality. Furthermore, this chapter presents a fact-checked, up-to-date approach for the ambiguous concept of what we consider “old vines”. Will it be possible, at last, to produce a standardised term for this?