Proton donors are substances that can release protons (H⁺ ions) in a solution, making them essential in acid-base chemistry. These substances are commonly known as acids. When a proton donor donates a proton to a base, it helps facilitate various chemical reactions, including neutralization processes. In the context of the Brønsted-Lowry theory, a proton donor is defined as a species that donates a proton to another species, known as a proton acceptor or base. This interaction is crucial in many biological and chemical systems, influencing everything from metabolism to industrial processes.