The Noble Ones
The 8 DN 16 DN 28 Dhp 255 Dhp 280 are those who have realized one of the 8 stages of holiness or sainthood, i.e. the 4 supermundane paths (magga) and the 4 supermundane fruitions (phala) of these paths.
There are 4 pairs:
The one realizing the path of Stream-winning
The one realizing the fruition of Stream-winning
The one realizing the path of Once-return
The one realizing the fruition of Once-return
The one realizing the path of Non-return
The one realizing the fruition of Non-return
The one realizing the path of Holiness
The one realizing the fruition of Holiness
Summed up, there are 4 noble individuals (ariya-puggala):
Stream-Winner (Stream-Enterer Dhp 178 SN 22:109 SN 23:7)
Through the path of Stream-winning (sotāpatti-magga) one 'becomes' free (whereas in realizing the fruition, one 'is' free) from the first 3 fetters (samyojana) which bind beings to existence in the sensuous sphere, to wit:
Attachment to mere rules and rituals
After the disappearance of the three fetters, the noble one has won the stream (to Nibbāna) and is no more subject to rebirth in lower worlds SN 12:41 SN 12:42, is firmly established, destined for full enlightenment SN 13 SN 15:10.
Through the path of Once-return (sakadāgāmi-magga) one becomes nearly free from the 4th and 5th fetters, to wit:
After the disappearance of the three fetters and reduction of greed, hatred and delusion, the noble one will return only once more; and having once more returned to this world, the noble one will put an end to suffering.
Through the path of Non-return (anāgāmi-magga) one becomes fully free from the above-mentioned 5 lower fetters.
After the disappearance of the five fetters the noble one appears in a higher world, and there he reaches Nibbāna without ever returning from that world (to the sensuous sphere).
Holy One (Perfected One SN 22:110 SN 23:8)
Through the path of Holiness (arahatta-magga) one further becomes free from the 5 higher fetters, to wit:
Craving for fine material existence
Craving for immaterial existence
Through the extinction of all cankers (āsava-kkhaya) the noble one reaches already in this very life the deliverance of mind, the deliverance through wisdom, which is free from cankers, and which the noble one has understood and realized.
The sevenfold grouping DN 33 MN 70 SN 12:27 SN 12:28 SN 12:49 SN 12:50 SN 22:76 of the noble disciples is as follows:
The noble one who is filled with resolution (adhimokkha) and, in considering the formations as impermanent (anicca), gains the faculty of faith, the noble one, at the moment of the path to Stream-winning is called a faith-devotee (saddhānusārī).
At the seven higher stages, the noble one is called a faith-liberated one (saddhā-vimutta).
The noble one who is filled with tranquility and, in considering the formations as miserable (dukkha), gains the faculty of concentration, the noble one in every respect is considered as a body-witness (kāya-sakkhī).
The noble one, however, who after reaching the absorptions of the immaterial sphere has attained the highest fruition (of Holiness), he is a both-ways-liberated one (ubhato-bhāga-vimutta).
The noble one who is filled with wisdom and, in considering the formations as not-self (anattā), gains the faculty of wisdom, he is at the moment of Stream-winning a Dhamma-devotee (dhammānusārī).
At the later stages a vision-attainer (ditthippatta).
At the highest stage a wisdom-liberated one (paññāvimutta).