Blockchain is a type of shared database that differs from a regular database in how it stores information; Blockchains store data in blocks, which are then linked to each other using cryptography.
As new data arrives, it is entered into a new block. Once a block is filled with data, it is appended to the previous block, causing the data to be chained together in chronological order.
Various types of information can be stored on a blockchain, but the most common use so far has been as a ledger of transactions.
In the case of Bitcoin, the blockchain is used in a decentralized manner, so that no one person or group has control - rather, all users collectively retain control.
Decentralized blockchains are immutable, which means that the data entered is irreversible. For Bitcoin, this means that transactions are permanently recorded and available for everyone to see.
A hard fork refers to a radical change in the protocol of a blockchain network that effectively results in two branches, one following the previous protocol and one following the new version.
Hyperledger is an open source community dedicated to developing a set of stable frameworks, tools and libraries for permissioned enterprise-grade blockchain deployment.
Hyperledger composer is a business-oriented set of tools for creating enterprise blockchain applications under the auspices of the Hyperledger project.
Hyperledger Explorer is a user-friendly web application tool used to view or access transactions, digital wallets, and other information stored on a Hyperledger blockchain deployment.
Hyperledger Sawtooth is an open-source enterprise blockchain-as-a-service platform that can run customized smart contracts without the need to know the underlying structure of the underlying system.
Smart contracts are self-executing lines of code in which the terms of an agreement between a buyer and a seller are automatically verified and executed over a computer network.
— Nick Szabo, American computer scientist who invented a virtual currency called “Bit Gold” in 1998,
An application-specific integrated circuit (ASIC) miner is a computerized device or hardware that uses an ASIC solely to mine bitcoin or another cryptocurrency.