This chapter presents a comprehensive recapitulation of the key technical advances discussed throughout the book. By reviewing the developments in contact-based, contactless, and advanced sensing systems, it synthesizes the core methodologies, datasets, and experimental findings that have shaped the field. The chapter also identifies several open challenges that must be addressed for palmprint recognition to be fully adopted in real-world applications. These include improving image acquisition under complex conditions, enhancing recognition robustness against intraclass variations, enabling efficient mobile deployment, and building ultra-large-scale datasets. By outlining future research directions across sensing, algorithmic modeling, and system integration, this chapter serves as both a concluding summary and a forward-looking roadmap for researchers and practitioners in the field of palmprint biometrics.