The Brønsted Acid-Base theory defines acids as substances that donate protons (H⁺ ions) and bases as substances that accept protons. This concept helps explain how different substances interact in chemical reactions, particularly in aqueous solutions. For example, when hydrochloric acid (HCl) dissolves in water, it donates a proton to water, forming hydronium ions (H₃O⁺) and chloride ions (Cl⁻). In this framework, the strength of an acid or base is determined by its ability to donate or accept protons. Strong acids, like sulfuric acid (H₂SO₄), readily donate protons, while strong bases, like sodium hydroxide (NaOH), easily accept them. This theory is fundamental in understanding various chemical processes, including neutralization reactions.