A blockchain is a decentralized, distributed, and public, digital ledger consisting of records called blocks, that are linked together using cryptography and Each block contains a cryptographic hash of the previous block, with a timestamp. As blocks each contain information about the block previous to it, they form a chain, called Blockchain.
Why blockchain is important:
The Blockchain is important because they are immutable, can easily save themselves from quantum computing hacks and other data breeze threats in the future, also their decentralization technique opens the space of data security and helps us to make trustless systems that do not need any third party to perform their tasks.
Key elements of a blockchain
Distributed ledger technology
All network participants have access to the distributed ledger and its immutable record of transactions. With this shared ledger, transactions are recorded only once, eliminating the duplication of effort that’s typical of traditional business networks.
No participant can change or tamper with a transaction after it’s been recorded to the shared ledger. If a transaction record includes an error, a new transaction must be added to reverse the error, and both transactions are then visible.
To speed transactions, a set of rules — called a smart contract — is stored on the blockchain and executed automatically. A smart contract can define conditions for corporate bond transfers, include terms for travel insurance to be paid and much more.
How blockchain works
A blockchain collects information together in groups, known as blocks, that hold sets of information. These transactions show the movement of an asset. The data block can record the information of your choice: who, what, when, where, how much, and even the condition — such as the temperature of a food shipment. Each additional block strengthens the verification of the previous block and hence the entire blockchain. This gives the Stability and immunity against tempering and becomes tamper-proof.
Benefits of blockchain
They’re global: which means that cryptocurrencies can be sent across the planet quickly and cheaply.
They increase privacy: Cryptocurrency payments don’t require you to include your personal information, which protects you from being hacked or having your identity stolen.
They’re open: Because every single transaction on cryptocurrency networks is published publicly in the form of the blockchain, anyone can scrutinize them. That leaves no room for manipulation of transactions, changing the money supply, or adjusting the rules mid-game. The software that constitutes the core of these currencies is free and open-source so anyone can review the code.
With blockchain, as a member of a members-only network, you can rest assured that you are receiving accurate and timely data, and that your confidential blockchain records will be shared only with network members to whom you have specifically granted access.
Consensus on data accuracy is required from all network members, and all validated transactions are immutable because they are recorded permanently. No one, not even a system administrator, can delete a transaction.
With a distributed ledger that is shared among members of a network, time-wasting record reconciliations are eliminated. And to speed transactions, a set of rules — called a smart contract — can be stored on the blockchain and executed automatically.
What’s the main advantage blockchains have over the old financial system?
Think about how much of your financial life takes place online, from shopping to investing – and how every single one of those transactions requires a bank or a credit card company or payment processor like PayPal in the middle of it. Blockchains allow for those transactions to happen without a middleman, and without the added costs and complexity that come with them.
What’s the future of blockchains?
The blockchain idea has turned out to be a platform that a huge range of applications can be built on top of. It’s still a new and rapidly developing technology, but many experts have described blockchain’s potential to change the way we live and work as being similar to the potential public internet protocols like HTML had in the early days of the World Wide Web.
The Bitcoin Cash and Litecoin blockchains work in a very similar way to the original Bitcoin blockchain. The Ethereum blockchain is a further evolution of the distributed ledger idea, because unlike the Bitcoin blockchain it’s not solely designed to manage a digital money. (That said Ethereum is a cryptocurrency and certainly can be used to send value to another person). Think of the Ethereum blockchain more like a powerful and highly flexible computing platform that allows coders to easily build all kinds of applications leveraging the blockchain.
For example, imagine a charity that wants to send money to a thousand people every day for a year. With Ethereum, that would only take a few lines of code. Or maybe you’re a video game developer that wants to create items like swords and armor that can be traded outside of the game itself? Ethereum is designed to do that, too.
NOTE: These Some definition is taken By IBM Website to search about BLOCKCHAIN Security you can Visit