Lenticular galaxies represent an intermediate type of spiral galaxy characterized by a prominent central bulge and a visible disk, but they lack the distinct spiral arms and ongoing star formation typical of pure spiral galaxies. They are often described as 'S0' galaxies and are thought to represent a phase of galaxy evolution, potentially resulting from interactions with other galaxies or from the gradual exhaustion of interstellar gas necessary for forming new stars. Structurally, these galaxies appear more disc-like than fully elliptical ones, yet their stellar population tends to be older and redder, indicating that the rapid, blue star formation phase has significantly slowed or ceased.