Dark matter is a form of matter that is invisible and does not interact with light or any electromagnetic radiation, making it undetectable by conventional means. It is hypothetical but strongly inferred from gravitational effects observed in the universe that cannot be explained by visible matter alone. These effects include the motion of galaxies within clusters, gravitational lensing, the large-scale structure of the cosmos, and patterns in the cosmic microwave background
. Dark matter constitutes about 85% of the total matter in the universe and about 26.8% of the total mass-energy content, far exceeding the roughly 5% composed of ordinary (baryonic) matter like atoms. It acts as a gravitational scaffold for the formation and evolution of galaxies and cosmic structures
. The leading scientific consensus is that dark matter is made up of some type of yet-undiscovered subatomic particles that interact primarily through gravity and not through electromagnetic forces. Candidates include weakly interacting massive particles (WIMPs), axions, or possibly a complex "dark sector" of particles. Despite extensive searches, these particles have not yet been directly detected
. In summary, dark matter is an invisible, non-luminous form of matter that exerts gravitational influence on visible matter and the structure of the universe but does not emit, absorb, or reflect light, making it fundamentally different from ordinary matter
