Dharma is the cosmic law of reality. It is simultaneously the Buddha’s teaching, meaning two very important things. First, it means that the Buddhist teachings and reality itself are one and the same; they correspond to each other. The Dharma is the fount of all things which lies beyond the universe and the wheel of becoming.
Secondly, since Dharma is beginningless and endless, the Buddha did not invent this teaching out of thin air. He discovered it as Siddhartha Gautama, and by attaining Buddhahood, Siddhartha became a perfect embodiment of the Dharma. Every Buddha represents the Dharma, and point to “the way things really are” in their own unique way. To gain insight is to know Dharma, and become one with it as a bodhisattva and then finally a Buddha. Namo Amitabha!