K mesons, also known as kaons, are a type of subatomic particle that belong to the family of mesons. They are composed of a quark and an antiquark, specifically a strange quark and either an up or down quark. K mesons come in several varieties, including K+, K-, and K0, each with different properties and charges. K mesons are important in the study of particle physics and CP violation, which helps scientists understand the differences between matter and antimatter. They are produced in high-energy collisions, such as those in particle accelerators, and have relatively short lifetimes, decaying into other particles quickly after their creation.