Buddha, Enlightened, Sangye; 佛陀, 正覺 (桑皆/桑傑); Tibetan: སངས་རྒྱས (sangye); Wylie: sangs rgyas; Sanskrit: buddha (布達);
The Buddha usually refers to Shakyamuni Buddha, the founder of Buddhism.
In general, a Buddha is someone who has awakened and enlightened from ignorance, eliminated from his/her mind stream all emotional and cognitive obscurations, stopped all sufferings and cycles of life and death, gained everlasting happiness and peace, through merits and wisdom.