This chapter will provide information on what Blockchain is and why it is used. It describes the basic concepts underlying Blockchain technology, such as distributed ledgers, consensus mechanisms, mining, smart contracts, P2P, and the classification of existing Blockchain systems. Next, it explores Blockchain applications in general, in businesses and society. Blockchain maybe used e.g., for fundraising, in education, and for provenance and authenticity registration. The last part of the chapter is devoted to application of Blockchain in general to applications in the hospitality and tourism industry. It considers how Blockchain makes it possible to create new types of platforms where transactions take place and the delivery of 'digital assets ', such as a hotel room booking, is not dependent on an intermediary. Other topics covered are tokenization, and the use of Blockchain in tracking baggage, loyalty programs, rating and reviews, payments, and digital identity.DOIhttps://www.doi.org/10.5038/9781732127593