Founder of BuddhIsm
who lived approximately 563-483 BCE. The Buddha, born Gautama Siddhartha, was a prince by birth, but at age 29 became dissatisfied with what he observed as an unjustifiable disparity between the luxury of his life, and the abject poverty he had observed within the community in general, and began practicing austere meditative practices. After six years, he abandoned the severe practices, and soon afterwards realized complete awakening/enlightenment. That enlightnment is called a state of "Bodhi," and hence the name "Buddha," or "enlightened one." The Buddha taught followers for 45 years until his death (considered to be the complete ending of the Buddha).
See [A Sketch of the Buddha's Life] for an excellent overview of the Buddha's life and teachings.
At least in the Westernized version of Buddhism I have heard, Buddha is not a deity. He is a man who achieved enlightenment in the Hindu sense in one lifetime instead of in many reincarnations in a state of self-awareness. He achieved this by living many different lifestyles including that of a decaying waterfowl. After enlightenment, he recognized his unity with the universal oneness, or atman. He thus got to stop being reincarnated, just like many other people who had achieved enlightenment over many lifetimes. Since the original Buddha, several other Buddhists have accomplished this feat and are thus called Buddha as well (i.e. the fat LaughingBuddha?
of China). If anything, the name for the sole deity in the universe is "atman".
- Some versions of Buddhism emphasize the Hindu legends more than others. The version you heard seems to be closer to the Hindu ideas of Buddhism. Most other versions do not focus on atman or reincarnation. Instead, the core of Buddhism is considered to be the teachings such as the NobleEightfoldPath? and the FourNobleTruths?.
- Also, while it is considered possible to achieve the same enlightenment as the historical Buddha, most Buddhists would not call those enlightened ones "Buddha"--that title is generally reserved only for the historical Buddha.
BuddhIsm has a whole bunch of branches, and some of the less-philosophical-more-ritualistic ones have him as a deity.