Dark matter is distinct from the ordinary matter that we are familiar with, such as sand, iron, electrons, and quarks. While dark matter is thought to interact gravitationally with ordinary matter, it does not interact strongly via the electromagnetic force, which is responsible for the interactions of electrons and quarks.
One of the primary reasons dark matter is considered distinct is that it does not interact with light or emit any detectable electromagnetic radiation. This is why it is called "dark" matter. Unlike ordinary matter, which can absorb, reflect, or emit light, dark matter does not directly interact with photons.
The properties of dark matter remain a mystery, and its exact nature is still unknown. Scientists believe that dark matter consists of some kind of non-baryonic particle, which means it is not composed of protons, neutrons, or electrons—the building blocks of ordinary matter. Potential candidates for dark matter particles include Weakly Interacting Massive Particles (WIMPs) and Axions, among others.
The study of dark matter is an active area of research in astrophysics and particle physics. Scientists use a variety of observational techniques, including studying the rotation curves of galaxies, gravitational lensing, and the cosmic microwave background radiation, to indirectly detect and study the effects of dark matter. However, direct detection of dark matter particles has proven challenging so far.
Therefore, while dark matter is believed to exist due to its gravitational effects on visible matter and the large-scale structure of the universe, it possesses properties that distinguish it from the known forms of matter.