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The phrase baryonic matter is used in astrophysics (especially, cosmology) for ordinary matter. In particular, it excludes dark matter. The term is often used in discussions of dark matter as well as statements regarding how much ordinary matter is in the observable universe or some portion of it (such as a particular galaxy cluster or galaxy). The phrase suggests it is matter made up of baryons (protons and neutrons), which ignores electrons, but by mass, their contribution is small, on the order of a tenth of a percent. In addition to dark matter, matter that is definitely not baryonic matter (non-baryonic matter or nonbaryonic matter) includes neutrinos, and other things that are not baryonic matter include fundamental (non-composite) bosons, such as photons, and black holes (though whether a black hole qualifies as matter perhaps depends upon the issue you are discussing).