D-mesons are subatomic particles made up of a combination of a charm quark and an antiquark. They belong to a family of particles known as mesons, which are formed by quark-antiquark pairs. D-mesons come in several varieties, including D⁰, D⁺, and D⁻, each differing in their charge and specific quark composition. These particles play a significant role in the study of particle physics and the behavior of strong interactions. D-mesons are particularly important for understanding CP violation, a phenomenon that helps explain the matter-antimatter asymmetry in the universe. Their properties are studied in high-energy particle accelerators.