Dark energy and dark matter are both terms used in cosmology to describe mysterious components of the universe, but they are fundamentally different concepts.
Dark Matter: Dark matter refers to a hypothetical form of matter that does not interact with light or other forms of electromagnetic radiation. It is called "dark" because it does not emit, absorb, or reflect light, making it invisible and difficult to directly detect. Its existence is inferred from its gravitational effects on visible matter and the large-scale structure of the universe. Dark matter is thought to make up a significant portion of the total matter in the universe, providing additional gravitational pull and affecting the motion of galaxies and galaxy clusters. Various observational and theoretical studies suggest that dark matter could consist of exotic particles that have not yet been directly detected.
Dark Energy: Dark energy, on the other hand, is a hypothetical form of energy that is believed to permeate all of space and drive the accelerated expansion of the universe. Unlike dark matter, which is associated with the gravitational effects of mass, dark energy is thought to be responsible for the observed accelerated expansion of the universe at large scales. Its nature and origin are not well understood. Dark energy is often associated with the cosmological constant or vacuum energy—a constant energy density that fills space uniformly.
In summary, dark matter is an unseen form of matter that affects the motion of galaxies and galaxy clusters through its gravitational influence, while dark energy is an unseen form of energy that is thought to be driving the accelerated expansion of the universe. While both concepts are still subject to ongoing research, they are distinct in terms of their effects, properties, and proposed explanations.