According to Buddhism, we living beings are trapped in the cycle of existence known as samsara. In samsara, we wander aimlessly and experience unbearable suffering—day and night, year after year, life after life—because of the tight grip of our grasping at self. In order to heal this disease-like condition, first we have to find its cause, and then we apply the medicine-like path of training to restore our original good health, which is enlightenment.
The Buddha’s first teaching was on the Four Noble Truths “Oh Bhikshus, there are four noble truths. They are the noble truths of suffering, the cause of suffering, the cessation of suffering and the path to the cessation of suffering.”
Theravada (or Hinayana) and Mahayana are the two major sects of Buddhism and are actually quite different from one another.
It is also called Southern Buddhism and holds that only monks can reach nirvana. This school is deeply monastic, seeing meditation as the main key to “salvation” and quite inwardly focused.
It is also called Northern Buddhism, and contends that even the laity can reach enlightenment. Meditation is vital for this school, but puts more emphasis on selflessness and altruism (i.e., helping others in order to help yourself ) to attain salvation (in their belief system); and thus is more outwardly focused than Theravada Buddhism. Additionally, about 700 years after Buddha died, this school had a tendency to see him as a divine. They also have many tantric and occult-like practices.
That being stated, a key textual authority providing some uniformity for most Buddhists is found in the Pali Canon The Pali Canon is divided into three parts each called pitaka or “basket” and thus has come to be known as the Tripitaka.
Vinaya Pitaka: (Basket of Order) Code of monastic discipline for the community of monks.
Sutra Pitaka: (Basket of Discourses) Conventional teachings believed to have come straight from Gautama Buddha or his closest followers.
Abhidhamma Pitaka: (Basket of Higher Teachings) Texts in which the Sutta teachings are arranged to help in the study of the nature of mind and matter.
There are several common beliefs that all Buddhists embrace. Front and center are the “Three Jewels” in which all Buddhists find refuge, reassurance, and dignity. They are the Buddha (the yellow jewel), the teachings (the blue jewel, or dharma), and the monastic order (the red jewel, or sangha). One can hear these three gems in the following popular mantra that Buddhist monks chant through the day:
Buddham Saranam Gachchami ( I take shelter in Buddha)
Dhammam Saranam Gachchami (I take shelter in dharma)
Samgham Saranam Gachchami (I take shelter in community with monks)