Altruism: Altruism is when an organism behaves in ways that benefit others while potentially harming itself. It's like when a soccer player takes a hard tackle to protect their goalie.
Kin Selection: Kin selection is an evolutionary strategy where organisms are more likely to help relatives, even at their own expense. It's like how you might share your lunch with your sibling even if it means you go hungry.
Social Behavior: Social behavior encompasses all interactions between members of the same species. Like how different players on a team communicate and coordinate during a game.