The term "청색 시대" (Blue Period) refers to a significant phase in the artistic career of Pablo Picasso, lasting from 1901 to 1904. During this time, Picasso predominantly used shades of blue and blue-green, reflecting themes of melancholy, poverty, and human suffering. His works often depicted solitary figures and scenes of despair, influenced by his experiences and the loss of his close friend, Carlos Casagemas. The Blue Period marked a departure from Picasso's earlier styles and laid the groundwork for his later developments, including the Rose Period. This era is characterized by its emotional depth and exploration of the human condition, making it a crucial part of modern art history.