Definition:
A Mandapa is a structure constructed in front of the main gate of a temple or other religious building.

Explanation:
- Mandapa: The mandapa is a columned or pillared hall that serves as a gathering place for worshippers before they enter the main sanctuary of the temple.
- Main Gate: The mandapa is typically located in front of the main gate or entrance of the temple.
- Function: The mandapa serves as a space where worshippers can gather, pray, and participate in rituals before entering the main sanctuary of the temple.
- Architectural Features: The mandapa is often characterized by its columns, which support the roof of the structure. These columns may be intricately carved or decorated with sculptures and reliefs.
- Symbolism: The mandapa is a significant architectural element in Hindu temple architecture, symbolizing the transition from the outer world to the inner sanctum of the temple, where the deity is enshrined.

Importance:
- The mandapa plays an important role in the overall design and layout of a Hindu temple, providing a space for worshippers to gather and participate in religious ceremonies.
- It also serves as a visual and symbolic link between the outer world and the inner sanctum of the temple, helping to create a sense of sacred space for worshippers.

In conclusion, the structure constructed in front of the main gate of a temple known as a mandapa serves both practical and symbolic purposes in Hindu temple architecture.