1. Buddhism: The Means
The Sangha

2. The Sangha This has several layers of meaning:
Worldwide community of Buddhists
The monastic community in general
A monastic community (Like Samye Ling)
The Aryasangha

3. The Sangha The Aryasangha
This includes all Buddhists (both lay and monastic) who have reached enlightenment.
Sometimes called the ‘noble sangha’.

4. Mahayana Bodhisattvas
Having attained liberation, arya bodhisattvas can:
Live as long as they wish.
Enter and arise from limitless types of meditation.
Find everything they need.
Be born whenever and wherever they wish.
They can go to any pure-land Buddha-field that they wish.
Understand all the words and meanings of the Dharma.

5. Therevada
In the Therevada tradition there are four stages of enlightenment:
Stream-enterer.
Once-returner.
Non-returner.
Arhat.

6. Therevada Stream-enterer.
The stream-enterer is said to have "opened the eye of the Dharma".
A stream-enterer will reach arhatship within seven rebirths.
The stream-enterer has attained perfect understanding of several aspects of the Dhamma including ‘right view’ and has complete confidence in The Three Jewels.
A Stream-enterer will not be reborn in any world lower than the human.

7. Therevada Once-returner.
They may have more than one rebirth still to go but only one as a human.
The once-returner has weakened the hold that the Three Root Poisons have over him/her to a greater degree than a stream-enterer.

8. Therevada Non-returner. Non-returners will not be reborn as a human.
They are reborn in one of the five "Pure Abodes", and will attain Nibbana from there.

9. Therevada Arhat. Requires no further training.
Is a fully enlightened person.
Upon death they will never be reborn in any world, having completely escaped Samsara. This is called parinibbana.