A function is a relation where each input have only one output . A relation is a set of order pairs.
The Independent variables is the Monsters and the dependent variable is the health points.
The domain is the monsters snail, shroom, red snail, blue snail, green mushroom, and horny mushroom. The range is 15,20,25,50,80, and 200.
If the domain and range got switched it would not pass the vertical line test thus making it not a function.