A lenticular galaxy is a type of galaxy that has characteristics of both spiral galaxies and elliptical galaxies. It features a central bulge and a disk but lacks the prominent spiral arms found in spiral galaxies. Lenticular galaxies are often classified as S0 in the Hubble sequence and are typically found in galaxy clusters. These galaxies contain older stars and have less interstellar gas and dust compared to spiral galaxies, which limits their ability to form new stars. Lenticular galaxies can be observed in various sizes and are important for understanding galaxy evolution and the transition between different galaxy types.