Hesychasm

i.e., the practice of the Jesus Prayer and other elements of Orthodoxy, is actually treated in some detail - though not perfectly as far as I have read - at Wikipedia. Although some Orthodox consider it 'just one way among many' in Orthodoxy, hesychasm's supporters sometimes claim it's what Orthodoxy is, as below (emphases added):

Hesychasm, rather than a facet of Orthodox theology, is presented as the embodiment of its sacred tradition. In reading Bishop [Hierotheos] Vlachos and some of his contemporaries it might seem to the inattentive student that the salvific role of hesychastic practice has been stressed at the expense of communal and cyclical liturgical observances, including the Holy Mysteries. Vlachos' contention is that the hesychastic lifestyle is solely capable of preparing one for participation in the Holy Mysteries and full appreciation of their meaning. Conversely, it is those ignorant of the truths of hesychasm who trivialise the sacred rites and stand thereby in peril. Fears that a resurgence of hesychasm could collapse the Church into isolated worshippers confined to their icon corners are dismissed as unfounded. Absent the hesychastic promise of purification, illumination and glorification, the Eastern Orthodox are reduced to long beards...long robes...long services' to paraphrase the words of the author's colleague, Fr John Romanides.