D^+ is a type of meson, which is a subatomic particle made up of a quark and an antiquark. Specifically, D^+ consists of a charm quark and an up antiquark. It is part of the D meson family, which plays a significant role in the study of particle physics and the interactions of fundamental particles. D^+ has a positive electric charge and a relatively short lifetime, decaying into other particles through weak interactions. Its properties help physicists understand the behavior of quarks and the forces that govern their interactions, contributing to the broader knowledge of the Standard Model of particle physics.