Cosmic shear refers to the slight distortion of galaxy shapes caused by the gravitational lensing effect of dark matter in the universe. This phenomenon occurs when the gravitational field of massive objects like galaxies and clusters of galaxies bends the path of light traveling from distant galaxies to Earth, causing them to appear stretched or distorted. Studying cosmic shear can provide insights into the distribution and properties of dark matter, as well as the large-scale structure of the universe. By measuring the extent of distortion in galaxy shapes, researchers can infer the gravitational influence of dark matter and map its distribution across the cosmos. Cosmic shear is commonly studied through large astronomical surveys that observe the shapes and positions of thousands or millions of galaxies. Analyzing these observations can help astronomers better understand the nature of dark matter, the evolution of the universe, and the underlying physics of gravity.