Tikkun Olam (repairing the world) is a core concept in Judaism, whereas doing good deeds, Mitzvot, and helping others are paramount to healing the world. Tikkun Olam is the act of making the world a better place for everyone, through actions, words, and thoughts that are positive, uplifting, and beneficial. Giving to others (Tzedakah), performing some of the Mitzvot, visiting the sick in hospitals, feeding the hungry, and generally speaking, all acts of kindness are a part of Tikkun Olam. This all culminates in various acts of social responsibility and justice and otherwise trying to fix whatever is seen as wrong in the world.
Tikkun Olam is the sole responsibility of human action and interaction, to perform good acts, to be good to their fellow living beings, and to seek out justice and equality.