Buddhism came into existence in India some 2,600 years ago when an Indian Prince, Siddhattha, became enlightened and hence came to be known as the Buddha, meaning the Enlightened One. His teaching is preserved in Buddhist scriptures known as the Tripitaka, which literally means the three baskets, namely the Vinaya or Vinaya-pitaka (monastic rules), Sutta or Suttanta-pitaka (collection of the teaching of the Buddha and His disciples) and Abhidhamma or Abhidhamma-pitaka (higher philosophy).
Buddhism is Atheistic; it does not give significance to divine beings. There are two major Schools in Buddhism: Theravada, the teaching as preserved by the elders and Mahayana, the later development. The former is practised in Sri Lanka, Thailand, Burma (Myanmar), Laos and Cambodia. The latter is more prevalent in China, Japan, Korea, Vietnam, Taiwan and Tibet.
In the First Sermon, Dhammacakkappavattana Sutta (the Discourse of the Turning of the Wheel of Dhamma or Truth), the Buddha pointed out the Middle Way which gives vision, which gives knowledge, which is conducive to calmness, insight, enlightenment and Nibbana (the state of being free from all defilements and suffering).
In one of His discourses, the Buddha summarized His teaching with the words "Vimutti or Spiritual Freedom from all defilements and sufferings is the Ultimate." When sending His first sixty disciples on their preaching tour, the Buddha said: "I, now, monks, am free from all bonds of gods and men. And you too, monks, are free from all bonds of gods and men. Travel, monks, for the welfare of the many, for the happiness of the many, for helping the world, for the good, welfare and happiness of gods and men."
From the Buddha's words, above mentioned, we can say that Nibbana or Vimutti is the main purpose of the preaching of the Buddha. He encouraged His disciples to walk the Middle Way in order to eradicate all defilements and sufferings and then, out of compassion for all, lend a helping hand to others.
In brief, the Buddha taught people how to be happy and prosperous both in a worldly as well as a spiritual sense. Those who follow His teaching can select their way of life practicable for themselves.