The Buddha's birth name was Siddhartha Gautama, and he was born a wealthy prince. Historians debate many details of his life, but he lived between the sixth and fourth centuries B.C.
The Buddha spent his early years in a sheltered palace that prevented him from seeing any suffering. He married and had a son before he ventured outside of the palace and saw people suffering. Buddha felt overwhelmed by what he saw and decided to become an ascetic in an effort to understand and overcome human suffering, which eventually led to his enlightenment.
Followers do not generally see Buddha as a god, but rather as a master teacher. He taught that all people are capable of reaching enlightenment. "Buddha" is a title that means "he who is awake." Some people refer to Buddha as Gautama Buddha to differentiate him from other Buddhas.
Although many people are familiar with depictions of the Buddha as a fat, happy-looking man, traditional depictions show him as slender. There are several stories about the identity of the fat Buddha, or Budai, including one that says he was an incarnation of the Buddha. Gautama Buddha spent his life as a traveling teacher, accepting hospitality from his students and walking everywhere, so he was likely quite thin.
Although the Buddha was originally an ascetic, his teachings focused on "The Middle Way," which advised moderation and an inward focus.