The kaddish prayer is said on various occasions, but is mostly known as ‘the prayer for the dead'. The prayer for the dead is called ‘kaddish yatom' (orphan's kaddish) in Hebrew. The words of the prayer do not refer to death directly, but sanctifies God's name. It prays for the establishment of God's kingdom in the near future. The prayer is said by a son or another direct relative at the end of the funeral ceremony and subsequently during the year of mourning and on the anniversary of the death.
The yizkor prayer is a prayer in memory of people who have died, which is said especially on the anniversary of the death.