Vamana is the avatar or incarnation of Vishnu, the Hindu God. In Hinduism, out of the 10 avatars of Lord Vishnu, Vamana is the fifth one. Vamana has a dwarf like appearance. As stated in the RigVeda, to measure the three worlds, heaven, earth and the space between the heaven and earth, Vishnu took just three strides.
According to later mythology, when Bali, the demon king ruled the whole Universe and the Gods had become powerless, Vamana the dwarf appeared and went to meet Bali in his palace and pleaded to him to grant him land enough for him to step over at three places only. His request was granted by Bali but he laughed at him. Vamana took a gigantic form and covered the whole Universe with just one step and covered the mid-world space between heaven and earth, with his second step. With this, Bali, the demon king was left with no place to go and promised to award Vamana with a third step. Happily Vamana used the pressure of his foot and pressed Bali down to go into hell and start ruling there instead.
Vamana is called the ‘Dwarf God’ or Vamandeva. He is called by other names like, Balibandhana (the one who confined Bali, the Demon King), Dadhivamana (mystic person or milk-dwarf), Upendra (Lord Indras’s younger brother) and Urukama (one of large step). In the Vedas he is described as the one who took back the ‘Triloka’ or the three worlds from King Bali. Vamana is represented as a gigantic dwarf with his one foot placed on the earth while the other foot is lifted as if he is going to take the next step.