In Hindu mythology, Vishnu is one of the principal deities of the Trimurti, representing the aspect of preservation and maintenance of the universe. He is known for his numerous avatars, including Rama and Krishna, through which he intervenes during times of chaos or decline in dharma (cosmic order). Vishnu is often depicted with blue skin, holding symbols like the conch, discus, and mace, each signifying his divine functions. His role underscores the balance between creation and destruction in Hindu belief.