A Root Node is the topmost node in a tree data structure, serving as the starting point for all other nodes. In a hierarchical arrangement, it has no parent and can have multiple child nodes. The root node is essential for organizing data, as it provides a clear structure for navigating through the tree. In computer science, tree structures are commonly used in various applications, such as file systems, databases, and search algorithms. The root node allows for efficient data retrieval and manipulation, making it a fundamental concept in data organization and management.