Research in clustering for Mobile Ad Hoc Networks (MANETs) focuses on developing intelligent, adaptive, and energy-efficient clustering algorithms to improve network scalability, stability, and resource management. Recent studies propose hybrid clustering schemes that combine fuzzy logic, swarm intelligence, and machine learning techniques for optimal cluster head selection and dynamic cluster maintenance. These methods aim to reduce communication overhead, balance energy consumption among nodes, and enhance routing efficiency. Trust-aware and mobility-based clustering mechanisms are also being explored to strengthen network security and maintain stable cluster structures under high node mobility. Overall, clustering continues to play a vital role in enhancing the performance, reliability, and longevity of MANET operations.