Stellar variability refers to the changes in brightness or other observable characteristics of stars over time. These variations can occur due to a variety of factors, including the star's internal processes, interactions with other stars or planets, or external influences such as stellar activity cycles or the presence of binary systems. Researchers study stellar variability to better understand the physical processes occurring within stars, as well as to track changes in stellar activity that can impact their evolution, behavior, and potential impact on surrounding objects. Observing and analyzing stellar variability can provide valuable insights into stellar dynamics, stellar atmospheres, and the overall evolution of stars over their lifetimes. This research area is essential for advancing our understanding of the universe and the behavior of stars within it.