Yes, dark matter is believed to make up the majority of the matter content in the universe. According to current scientific understanding, ordinary matter, which includes atoms and subatomic particles, accounts for only about 5% of the total mass-energy content of the universe. The remaining 95% is composed of dark matter and dark energy.
Dark matter is a hypothetical form of matter that does not interact with light or other electromagnetic radiation, making it difficult to directly observe or detect. Its presence is inferred from its gravitational effects on visible matter and the large-scale structure of the universe.
Estimates suggest that dark matter contributes around 27% of the total mass-energy content of the universe. This estimation is based on observations of the cosmic microwave background radiation, the distribution of galaxies, and the motion of stars within galaxies. However, the exact nature and composition of dark matter remain unknown, and it continues to be an active area of research in astrophysics and particle physics.