“…all in all the premises of breath meditation are based on four observations about the mind that the Buddha called Noble Truths:
1) The mind experiences stress and suffering.
2) The stress and suffering come from the way the mind shapes its experience through its actions driven by ignorance.
3) That ignorance can be ended, opening your awareness to an unconditioned dimension free of stress and suffering.
4) That dimension, even though it’s unconditioned, can be reached by training the mind in the skillful qualities of virtue, concentration, and discernment.”
The purpose of breath meditation is to help with that training.
from “With Each and Every Breath. A Guide to Meditation.” 2013. Thanissaro Bhikkhu (Geoffrey DeGraff)