We may not know what dark matter is, but that hasn't stopped scientists from trying to understand its role in the Universe. The Lambda-Cold Dark Matter (CDM) model is the standard model that explains the cosmos the best, although it's not the only model. It makes a number of predictions about dark matter and researchers look for opportunities to test those predictions. The results either help confirm or deny the model. Dark matter is the Universe's scaffolding, and galaxies form in dark matter..