1 History 2 Structure 2.1 Blocks - Block Time - Hard Forks 2.2 Decentralization 2.3 Openness - Permissionless - Permissioned (private) blockchain - Disadvantanges of Private Blockchain - BlockChain Analysis 3 Uses 3.1 Cryptocurrencies 3.2 Smart contracts 3.3 Financial services 3.4 Video games 3.5 Energy trading 3.6 Supply chain 3.7 Domain Names 3.8 Other uses 4 Types 4.1 Public blockchains 4.2 Private blockchains 4.3 Hybrid blockchains 4.4 Sidechains 5 Academic research 5.1 Adoption decision 5.2 Collaboration 5.3 Blockchain and internal audit 5.4 Energy use of proof-of-work blockchains 5.5 Journals A blockchain , originally block chain , is a growing list of records, called blocks , that are linked using cryptography. Each block contains a cryptographic hash of the previous block, a timestamp, and transaction data (generally represented as a Merkle ...