Hydrogen is a clean fuel, a versatile energy carrier, and seems to be the answer to the climate change challenge. Why is everyone talking about it, and how is it going to replace traditional fuels? This modularized course provides a comprehensive overview on hydrogen as an energy carrier, with focus on fuel cell as hydrogen conversion technology. Hydrogen production and storage and their role in decarbonization will be covered. Different fuel cell technologies will be analyzed and discussed to present benefits and challenges in the use of hydrogen for power production, urban mobility, aviation, transportation, residential sector and much more. The learners will be able to combine the available modules to create their personalized education based on their needs and get insights on where and when hydrogen can play a role in a carbon-free society.