Who was Siddhartha Gautama?
In short, Siddhartha Gautama is the founder of the religious-philosophy, referred to as Buddhism. Living more than 2,500 years ago, the Buddha was born in modern day Nepal, in the Gaṇarajja (Clan-Kingdom) of the Sakyas (The Buddhas Family Clan). The Buddha set out to seek the end of suffering presented by life, and achieved enlightenment at the age of 35, and taught his teachings for 45 years, before entering Parinibbāna...

THE FOUR NOBLE TRUTHS OF BUDDHISM
The Cause of Suffering
(Pali and Sanskrit: Samudaya)
The cause of suffering is fundamental ignorance or misunderstanding about our own nature and the nature of reality. We suffer because of our mistaken belief that things, including us, are separate, independent, and solid. The painful and futile struggle to maintain this delusion of ego is known as Saṃsāra, or cyclic existence.
The End of Suffering
(Pali and Sanskrit: Nirodha)
The good news is that our obscurations are temporary. Therefore, suffering can end because our obscurations can be purified, and the awakened mind is always available. This state is referred to as Enlightenment, or Nibbana, which is the complete cessation of suffering. It is a state of freedom, peace, and liberation from the cycle of birth, death, and rebirth.
The Path
(Pali: Magga; Sanskrit: Marga)
The fourth and final truth tells us that by spiritual practice, living ethically, and developing wisdom, we can take the same journey to enlightenment and freedom from suffering that the buddhas do. By following the Noble Eightfold Path, we, too, can become Enlightened.
What is the Noble Eightfold Path?
The Noble Eightfold Path consists of eight practices: Right view, Right resolve, Right speech, Right conduct, Right livelihood, Right effort, Right mindfulness, and Right Samadhi ('meditative absorption or union'; alternatively, equanimous meditative awareness).