Nebula formation is the process by which vast clouds of gas and dust in outer space condense and collapse under the force of gravity, leading to the formation of new stars and planetary systems. Nebulae come in various shapes and sizes, and are classified into different types such as emission nebulae, reflection nebulae, and dark nebulae. The study of nebula formation involves research on the physical conditions and processes that govern the evolution of these interstellar clouds, as well as their role in the formation and evolution of galaxies. Researchers often use telescopes and other observational tools to study nebulae and gain insights into the dynamics of star formation and the lifecycle of cosmic matter.