The Three Jewels, also called the Three Treasures, the Three Refuges, are the three things that Buddhists take refuge in, and look toward for guidance, in the process known as taking refuge.
depending on one's interpretation, can mean the historical Buddha (Shakyamuni) or the Buddha nature—the ideal or highest spiritual potential that exists within all beings;
the teachings of the Buddha.
The community of those who have attained enlightenment, who may help a practicing Buddhist to do the same. Also used more broadly to refer to the community of practicing Buddhists.
"Buddha", "Sutra" and "Stupa" represent "Buddha", "Dharma" and "Sangha", that means taking refuge(support) with the Three Jewels.