Final answer:
The railing from the Great Stupa serves symbolically as a demarcation between the secular and the sacred, adorned with artistic depictions that reflect Buddhist teachings and the path of enlightenment.
Step-by-step explanation:
The railing from the Great Stupa symbolically serves as a boundary that separates the mundane world outside from the sacred world within. These railings, some dating back to 150 BCE with additions from the Gupta period, not only have a protective function but also are embellished with figures and depictions related to the life of the Buddha and his teachings. They represent a transition from the physical to the spiritual, emphasizing the path of enlightenment that Buddha took, which is further highlighted by the presence of the tree under which Buddha is said to have gained his enlightenment. The architectural elements around the Great Stupa and the rituals associated with it reflect the greater Buddhist principles and serve as a testament to the religious, cultural, and artistic values of the societies that contributed to their construction and maintenance.