Fetter is a mental fetter, chain or bond shackles a sentient being to saṃsāra, the cycle of lives with dukkha (suffering). By cutting through all fetters, one attains Nibbāna.
According to the Sutta Piṭaka, the 10 fetters to be renounced in order to reach the final stage of enlightenment (Nibbāna) are the following.
5 big fetters (belonging to the lower world)
1. sakkāya-diṭṭhi : personality-belief
2. vicikicchā : sceptical doubt
3. sīlabbata-paramāsa : clinging to mere rules and ritual
4. kāma-rāga (kāmacchanda) : sensuous craving, sensual desire
5. vyāpāda : ill-will
5 small fetters (belonging to the higher world)
6. rūpa-rāga : craving for fine-material existence
7. arūpa-rāga : craving for immaterial existenc
8. māna : conceit
9. uddhacca : excitement
10. avijjā : ignorance
By renouncing these 10 fetters, suffering is completely conquered.