Young stellar objects (YSOs) are stars that are in the early stages of their formation. They are typically found in dense regions of interstellar gas and dust, where gravity causes material to collapse and form a protostar. This process can take millions of years, and during this time, the protostar gathers mass and begins to heat up. As YSOs evolve, they may develop a surrounding disk of gas and dust, which can eventually lead to the formation of planets. These objects are crucial for understanding stellar evolution and the birth of planetary systems, including our own Solar System.