Blockchain

Blockchain is a chain of blocks. 
The Blockchain is a type of software to register information 
The Blockchain is a type of software to register information securely in a public record
The Blockchain is a type of software to register information securely in a public record that is available freely to every man. Information that is registered may be called transactions, such as the registration of car ownership is usually a registration of a transaction—or is registered as a transaction anyway—("the car came into your ownership.") E.g. the car dealer owned the car, but a transaction took place and now it is registered in your name to show that you are the current owner of the car. To prevent or minimize dispute, the record of this is kept as public and secure as possible, but it can, incredibly, still be anonymous (as it is private-key dependent). 
To minimize or prevent theft, the record of this is increasingly securitised, such as through designing the software which stores and handles the information as tamper-resistant. Blockchain is a tamper-resistant software for recording transaction. It is a public record. It is used e.g. to hold tamper-proof records of home ownership. As a record of transactions it is definitely a ledger. The records are called blocks; indeed, blocks on the ledger. These recorded blocks are linked, as links in a chain. Thus blockchain — a chain of blocks. The blocks form chronologically. 
Anti-tamper software (or tamper-resistant software) is software which makes it harder for an attacker to modify it. The Blockchain is a digital ledger in which transactions made in bitcoin or another cryptocurrency are recorded chronologically and publicly. The Blockchain is the decentralized sharing of simple data or information in a secure manner without having a central authority or intermediary to perform the information sharing function. A global network of computers uses blockchain technology to jointly manage the database that records Bitcoin transactions. 
Satoshi Nakamoto's development of Bitcoin in 2008[1a][1b]–2009[1c][1d] has often been hailed as a radical development in money and currency, being the first example of a digital asset which simultaneously has no backing or intrinsic value[2] and no centralized issuer or controller. However, another, arguably more important, part of the Bitcoin experiment is the underlying blockchain technology as a tool of distributed consensus, and attention is rapidly starting to shift to this other aspect of Bitcoin. Commonly cited alternative applications of blockchain technology include using on-blockchain digital assets to represent custom currencies and financial instruments (colored coins),[3] the ownership of an underlying physical device (smart property),[4] non-fungible assets such as domain names (Namecoin),[5] as well as more complex applications involving having digital assets being directly controlled by a piece of code implementing arbitrary rules known as smart contracts[6] or even blockchain-based decentralized autonomous organizations (DAOs).[7]
Sir Nick Land "The blockchain solves the problem of spacetime.": So we have now artificial absolute 
time for the first time ever in human history. And this therefore is 
scrambling these narratives it’s scrambling our sense of pre and post, 
what is the actual set of successions in the most concrete sense …—Nick Land on Blockchain Revolution 
See blockchain managed contract lifecycles.Imagine sitting on a train and everyone telling the person next to them what they had for breakfast. No one person (or link) knows what everyone had for breakfast, but collectively the knowledge of the whole train carriage knows everything about the various breakfasts that were eaten on that particular morning. Put into more practical uses, banks and financial institutions use this all the time to make a shared ledger of time-stamped, encoded transactions (or blocks) that are shared across a network of institutions.
Smart contracts explained
If you take these blocks and add some coding to them in simple logic such as “if X happens, then do Y,” you arrive at the basics of the “smart contract.” Again, put in more practical terms, organizations will code a transaction such as “if the price of gold hits X per ounce, then sell the gold.” [ Craig Conte ]What everyone is getting excited about is that if a smart contract works (and they do), and entities can effectively perform transactions in real time without extra cycles or reviews, and if these transactions are just logic based, couldn’t we just push the limits of the “coding” to get to more sophisticated contracting [ Craig Conte ]
The blockchain is a connectionism.
=== History ===
In 1998, Wei Dai's b-money[9] became the first proposal to introduce the idea of creating money through solving computational puzzles as well as decentralized consensus, but the proposal was scant on details as to how decentralized consensus could actually be implemented. In 2005, Hal Finney introduced a concept of reusable proofs of work,[10] a system which uses ideas from b-money together with Adam Back's computationally difficult Hashcash[11] puzzles to create a concept for a cryptocurrency, but once again fell short of the ideal by relying on trusted computing as a backend. In 2009, a decentralized currency was for the first time implemented in practice by Satoshi Nakamoto,[1c][1d] combining established primitives for managing ownership through public key cryptography with a consensus algorithm for keeping track of who owns coins, known as "proof of work."
Category:Technology