What is the essence of blockchain?
A blockchain – originally block chain – is a continuously growing list of records, called blocks, which are linked and secured using cryptography. Each block typically contains a hash pointer as a link to a previous block, a timestamp and transaction data.
Where does the blockchain philosophy come from?
The first work on a cryptographically secured chain of blocks was described in 1991 by Stuart Haber and W. Scott Stornetta. The first distributed blockchain was then conceptualised by an group known as Satoshi Nakamoto in 2008 and implemented the following year as a core component of the digital currency bitcoin, where it serves as the public ledger for all transactions.
How will the blockchain technology possible affect society?
The use of blockchains promises to bring significant efficiencies to global supply chains, financial transactions, asset ledgers and decentralized social networking. Blockchains have the potential to reduce systemic risk and financial fraud. They automate processes that were previously time-consuming and done manually. Major applications of blockchains include cryptocurrencies, smart contracts e.g. in all kind of global markets.
Note the difference between blockchain and altchains:
Alternative blockchains, also known as altchains, are based on bitcoin technology in concept and/or code. These designs generally add functionality to the blockchain design.