Vishnu is one of the principal deities in Hinduism, known as the preserver and protector of the universe. He is often depicted with a blue complexion and four arms, holding a conch, a discus, a mace, and a lotus. Vishnu's role is to maintain cosmic order and restore balance whenever evil threatens to disrupt it. Vishnu is also famous for his ten avatars, or incarnations, which include Rama and Krishna. Each avatar appears in different forms to tackle specific challenges in the world. Devotees worship Vishnu to seek his blessings for peace, prosperity, and protection from harm.