The first four Caliphs, who successively ruled Muslims after the Prophet’s death. They are Abu Bakr as-Siddīq, ‘Umar ibn al-Khattāb, ‘Uthmān ibn ‘Affān, and ‘Ali ibn Abi Tālib (may Allah be pleased with them).
Tījāniyyah
The Companions regarding whom the Prophet, may Allah’s peace and blessings be upon him, testified that they would enter Paradise. This includes the ten Companions known with this title as well as others.
Those who come after the first three best generations (since the start of the Islamic era) and pursue the path of the people of religious innovations and deviant whims.
The Companions whom the Prophet, may Allah's peace and blessings be upon him, assigned to write down and record the Qur’an that was revealed to him.