In the context of cosmology, including discussions of dark matter and the evolution of the universe, the term "baryonic matter" refers to the so-called ordinary matter described by the Standard Model. The atoms and molecules we are made of are considered baryonic matter. Axions and WIMPs are examples of nonbaryonic matter. Most of the dark matter is presumed to be nonbaryonic; however, no nonbaryonic matter has been directly detected in experiments.
