What is a stellar cloud?

A stellar cloud, often referred to as a molecular cloud or nebula, is a vast region in space filled with gas and dust, primarily composed of hydrogen molecules. These clouds are the primary sites of star formation, as the dense areas within them can collapse under gravity to form new stars. Stellar clouds can vary in size and density, and they often produce complex structures that can include stellar nurseries, where new stars are birthed, as well as remnants from previous stellar evolution.