Tikun.
The process of hardship, pain, and challenges that we experience in life in order to correct our vessel and reveal Light. It helps us improve our souls and or ‘pay’ for past sins.
This process can continue through many lifetimes. It will end in the Final Redemption.
Rabbi Yosef Yozel Horowitz (Hebrew: יוסף יוזל הורוביץ), also Yosef Yoizel Hurwitz, known as the Alter of Novardok (1847–1919), was a student of Rabbi Yisroel Salanter,
Son of the RAMBAM.
Rabbi Boruch of Medzhybizh was a grandson of the Baal Shem Tov. Reb Boruch was the first major "rebbe" of the Hasidic movement to hold court in Mezhbizh in his grandfather's hometown and Beis Medrash, which he inherited.
Rabbi Dov Baer ben Avraham of Mezeritch, also known as the Maggid of Mezritch, was a disciple of Rabbi Yisrael Baal Shem Tov, the founder of Hasidic Judaism, and was chosen as his successor to lead the early movement