ti-ratana: 'Three Jewels' or Three Gems, which by all Buddhists are revered as the most venerable things, are the Buddha, the Dhamma and the Holy Saṃgha.' i.e.: the Enlightened One; the law of deliverance discovered, realized and proclaimed by him; and the Community of Holy Disciples and those who live in accordance with the Law. - The contemplations of the 3 Jewels belong to the 10 contemplations (anussati q.v.).

Buddhist Dictionary, Manual of Buddhist Terms and Doctrines, by NYANATILOKA MAHATHERA