Cosmic variance is a statistical concept in cosmology that arises from the fact that we observe the universe from a limited vantage point. It refers to the inherent variability or fluctuations in the properties of large-scale structures in the cosmos due to the finite size of the observable universe. The universe is not perfectly uniform on large scales, and its structures, such as galaxies, clusters, and superclusters, are distributed unevenly. Because our observations are limited to a finite volume of the universe, we may sample regions that are more or less dense with matter, leading to variations in the statistical properties of these structures. Cosmic variance is particularly relevant when studying the cosmic microwave background radiation, large-scale galaxy surveys, or other cosmological observations.