The stellar halo is a diffuse and relatively faint component of galaxies that surrounds the more densely packed central regions, such as the bulge and disk. It is made up of old, metal-poor stars that typically have orbits that extend far beyond the main body of the galaxy. Research on the stellar halo aims to understand its formation and evolution, as well as its role in the overall structure and dynamics of galaxies. Scientists study the stellar halo through observations of individual stars, globular clusters, and stellar streams that populate this region. By studying the stellar halo, researchers can gain insights into the processes of galaxy formation and evolution, the accretion of smaller satellite galaxies, and the distribution of dark matter in the outer regions of galaxies. This research area is important for understanding the overall structure and history of galaxies in the Universe.