From Libertarian Wiki

Individualism is the moral stance, political philosophy, ideology, or social outlook that stresses independence and self-reliance. Individualists promote the exercise of one's goals and desires, while opposing most external interference upon one's choices, whether by society, or any other group or institution. Individualists believe in the supremacy of the individual.

Individualism is opposed to collectivism, which stresses that communal, community, group, societal, familial or national goals should take priority over individual goals.