About the Mourner's Kaddish:

One of the most sacred rituals observed by all Jews throughout the generations is the practice of reciting the Mourner's Kaddish prayer for the merit of the departed soul of one's father or mother. It is said at the funeral, during the week of mourning (shiva), for the following 11 months, and then every year on the anniversary of passing. Read About Kaddish, the Jewish memorial prayer