Friendship is a relationship of mutual affection between people ... certain characteristics are present in many types of such bonds. Such characteristics include affection; kindness, love,
virtue, sympathy, empathy,
honesty, altruism, loyalty,
mutual understanding and
compassion, enjoyment of each other's company, trust, and the ability to be oneself, express one's feelings to others, and make mistakes without fear of judgment from the friend.
-Wikipedia