Graph reachability queries, which determine whether a path exists between two vertices in a graph, are a foundational problem in graph analytics. This survey provides a comprehensive review of techniques for efficient graph reachability querying, including static and dynamic approaches, indexed and online methods, and recent advancements. Detailed discussions explore various design choices for efficiently handling graph reachability queries, emphasising their applicability, limitations, and performance trade-offs. Additionally, we outline key open challenges and potential future directions to advance this field. This survey aims to guide researchers in navigating and advancing the state-of-the-art in graph reachability queries.