Ravana is depicted in art with up to ten heads, signifying his knowledge of Vedas and Shastras. His ten heads earned him the names "Dashamukha" (दशमुख, The ten-faced), "Dashagriva" (दशग्रीव, The ten-necked) and "Dashakantha" (दशकण्ठ, Ten Throats). He also had twenty hands, signifying greed and never-ending want. Ravana was born to the Brahmin sage known as Vishrava. His mother was the Daitya princess Kaikesi. Kaikesi's father, Sumali, king of the Daityas, wished her to marry the most powerful being in the mortal world, so as to produce an exceptional heir. He rejected the kings of the world, as they were less powerful than him. Kaikesi searched among the sages, and finally chose Vishrava. Vishrava warned her that as she approached him at an inappropriate time, their children would tend towards evil, but accepted her nevertheless. As such, Ravana was partly Daitya, and partly Brahmin.
Ravana was the eldest of Vishrava's children, given the name Dashanana/Dasagriva at birth - he was born with ten heads (Some say the ten heads were due to the reflections of a crystal necklace gifted to him by his father at the time of his birth or he had the mental strength of 10 people).
His brothers were Vibhishana and Kumbhakarna. Through his mother, he was related to the daityas Maricha and Subahu. Kaikesi also produced a daughter, meenakshi (meaning: girl with fish like eyes), although later she was dubbed the infamous Shoorpanakha (the one with sharp fingernails). Nakha means nails in sanskrit.
His father Vishrava noted that while Ravana was aggressive and arrogant, he was also an exemplary scholar. Under Vishrava's tutelage, Ravana mastered the Vedas and the holy books and also the arts and ways of Kshatriyas. Sumali, his grandfather, worked hard in secret to ensure that he retained the ethics of the Daityas.
Ravana had an ultimate knowledge but just because of his proud he became the symbol of evil.
So always use ur knowledge to help the world not just showing ur attitude..............