The video shows a person using a level to check the flatness of a wooden board. The person is seen kneeling on the floor and placing the level on the board. They then adjust the level to ensure that it is level with the board. After that, they use a hammer to tap on the level to secure it in place. The person then checks the level again to make sure it is still level. Finally, the person removes the level from the board and the video ends.