Buddhism is a spiritual tradition that originated in India more than 2,500 years ago. Buddhism arose as the result of Siddhartha Gautama's quest for enlightenment. Although many Buddhist traditions exist, such as Theravada, there are certain ideas that are common to and shared by all Buddhists. As of 2009, there were approximately 375 million Buddhists in the world.

Four Noble Truths

Developed by the Buddha, the Four Noble Truths are a main tenet of Buddhism. The truths teach that all life is suffering and that this is caused by craving and aversion. You can overcome this suffering, however, and attain true happiness. When you learn to give up useless cravings and desires, you can dedicate more time to helping others. This is known as nirvana: the liberation and freedom from suffering.

Eightfold Path

The Buddha taught that following the Eightfold Path is the way to reach the state of nirvana. In essence, this path consists of understanding and following the Four Noble Truths, conquering negative thoughts, being mindful and practicing meditation. Living life according to the Five Precepts is an important part of following the Eightfold Path. These are the rules that Buddhists live by: Do not harm others; do not steal; do not lie; do not misuse sex; and do not consume alcohol or drugs.

Karma

Another main idea of Buddhism, karma is the belief that every action we take has an effect. To illustrate this idea, Buddhists use the agricultural metaphor that sowing good or bad seeds will result in good or bad fruit. For Buddhists, karma is used to explain inequality and is a reminder that they must take responsibility for their actions.

Reincarnation

Buddhists also believe in reincarnation, the endless cycle of life, death and rebirth. Karma determines where a person will be born and his status in the next life; good karma leads to a heavenly realm, while bad karma can lead to rebirth as an animal or torment in hell. In Buddhism, there are six realms into which a person can be reborn; these realms are depicted in the Bhavachakra, or Wheel of Life. Only with enlightenment can a person be freed from the cycle of reincarnation.