What is Blockchain?

Blockchain is a digital database or ledger that is distributed among the nodes of a peer-to-peer network

Bitcoin is an example, it is used for maintaining a secure and decentralized record of transactions.

Why it's useful? Because it guarantees the fidelity and security of a record of data and generates trust without the need for a trusted third party.

What is the difference between a blockchain database and a regular database? It`s all in the way the data is structured.

A blockchain collects information together in groups, known as blocks, that hold sets of information.
These blocks are like a data bucket that can be filled, closed and linked to the previously filled block, forming a chain.
Once a block is filled and linked, a new block is created, data is stored in it, until it is filled and linked. This process is repeated.

A regular database is structured into tables with rows and columns (think like a spreadsheet). Each row has a key and it`s with that key that a row of data can be obtained for consulting it and editing it. With a blockchain, the data is stored in chunks (blocks) and can be traced back to the first block that was created, filled and linked.

But the goal of the blockchain is to store data not to edit it after it was stored.
The core principle of the blockchain is to become an immutable ledger.

Blockchains are also known as distributed ledger technology (DLT).

What are the steps to complete a transaction?

1. A new transaction is entered.
2. The transaction is then transmitted to a network of peer-to-peer computers scattered across the world.
3. This network of computers then solves equations to confirm the validity of the transaction.
3. Once confirmed to be legitimate transactions, they are clustered together into blocks.
4. These blocks are then chained together creating a long history of all transactions that are permanent.
5. The transaction is complete.

Even though blockchains are mostly known to be used to store cryptocurrencies transaction history, they can also be used for
legal contracts or product inventories. Basically, anything that required transactions to be stored in a way that they must not be modified.
Blockchain provides redundancy but also fidelity of the data stored in it.

Since blockchains are distributed among a peer-to-peer network of computers, all transactions are inherently transparent. They can be viewed by either having a personal node or using blockchain explorers that allow anyone to see the transactions occurring live.

Each node has its own copy of the chain that gets updated as fresh blocks are confirmed and added.

Visit https://www.blockchain.com/exp... to see an example of blockchain explorer. On this website, transaction and blockchain details can be viewed. 

By Helene Voyer

For more information : https://www.investopedia.com/t...