Vmax refers to the maximum rate at which an enzyme can catalyze a reaction when it is saturated with substrate. It is a key parameter in enzyme kinetics, helping to understand how efficiently an enzyme works. Vmax is influenced by factors such as temperature, pH, and the presence of inhibitors or activators. In the context of the Michaelis-Menten model, Vmax is often used alongside the Michaelis constant (Km) to describe the relationship between substrate concentration and reaction rate. This model is fundamental in biochemistry for analyzing enzyme behavior and understanding metabolic pathways.