Explanation: While struggling for Enlightenment, Buddha had discovered Dhamma/Four Noble Truths which form the central teachings of Buddhism. The Four Noble Truths are:

• The Truth of Suffering (Dukkha): Buddha taught that everything is suffering (sabbam dukkham). It refers not only to the actual pain and sorrow experienced by an individual, but also to the potential to experience these things.
• The Truth of the Cause of Suffering (Samudaya): Suffering is part of living and there is a reason behind it. Desire (Trishna) is the main cause of suffering.
• The Truth of the End of Suffering (Nirodha): This suffering can be ended by attaining Nirvana/Nibbana.
• The Truth of the Path Leading to the End of Suffering (Astangika-Marga): There is a path that leads to the end of suffering.

Source: Tamil Nadu NCERT