This chapter provides a comprehensive overview of how hydrogen forms a critical link in the hydrogen energy value chain and plays an important role in global decarbonization efforts. Hydrogen has been extensively utilized in petroleum refining and the chemical industry, particularly for methanol and ammonia production. However, growing concerns over climate change and energy security have made the utilization of hydrogen in various sectors more attractive. This chapter provides an overview of hydrogen utilization pathways, encompassing conventional applications in refineries and the chemical industry, as well as emerging uses in iron and steel manufacturing through hydrogen-based direct reduction, expanding roles in power generation, energy storage, industrial heat, buildings, and transportation. It also discusses current global and regional hydrogen demand trends, technology status, and their transition from fossil-based hydrogen toward green hydrogen with carbon capture and storage. The key hydrogen conversion technologies, including internal combustion engines and fuel cells, are examined in detail, along with their performance characteristics and challenges. Additionally, it also highlights global and India's hydrogen strategies and policy initiatives that are shaping future deployment.