Katara is a character from the cartoon Avatar: The Last Airbender.
In Avatar, there are four nations: The Air Nomads, the Water Tribes, the Earth Kingdom, and the Fire Nation. Some people are benders of their respective element(air for Air Nomads, water for Water Tribes, etc.), although most people lack the ability to bend. Bending is essentially being able to manipulate whatever element it is. As Katara is a waterbender, she can control water. Late in season 1, she learned to draw water from the air, and in season 3, episode 8, she learned to control people by manipulating the water in their blood. She can also freeze water and melt ice, and in season 1, episode 16, learned that she could heal wounds using water(although she didn't really learn how to use this skill until approximately season 1 episode 18.
Water Pouch Edit
Katara has a fur pouch to hold water. She uses the water from it when there's no water in the air to use, and then bends the water back in.