What Is a Blockchain?
A blockchain is a distributed database or ledger that is shared among the nodes of a computer network. As a database, a blockchain stores information electronically in digital format. Blockchains are best known for their crucial role in cryptocurrency systems, such as Bitcoin, for maintaining a secure and decentralized record of transactions. The innovation with a blockchain is that it guarantees the fidelity and security of a record of data and generates trust without the need for a trusted third party.
One key difference between a typical database and a blockchain is how the data is structured. A blockchain collects information together in groups, known as 'blocks', that hold sets of information. Blocks have certain storage capacities and, when filled, are closed and linked to the previously filled block, forming a chain of data known as the blockchain. All new information that follows that freshly added block is compiled into a newly formed block that will then also be added to the chain once filled.
A database usually structures its data into tables, whereas a blockchain, as its name implies, structures its data into chunks (blocks) that are strung together. This data structure inherently makes an irreversible timeline of data when implemented in a decentralized nature. When a block is filled, it is set in stone and becomes a part of this timeline. Each block in the chain is given an exact timestamp when it is added to the chain.
How Does a Blockchain Work?
The goal of blockchain is to allow digital information to be recorded and distributed, but not edited. In this way, a blockchain is the records of transactions that cannot be altered, deleted, or destroyed.
First proposed as a research project in 1991, the blockchain concept predated its first widespread application in use: Bitcoin, in 2009. In the years since, the use of blockchains has exploded via the creation of various cryptocurrencies, decentralized finance (DeFi) applications, non-fungible tokens (NFTs), and smart contracts.
Imagine that a company owns a server farm with 10,000 computers used to maintain a database holding all of its client’s account information. This company owns a warehouse building that contains all of these computers under one roof and has full control of each of these computers and all of the information contained within them. This, however, provides a single point of failure. What happens if the electricity at that location goes out? What if its Internet connection is severed? What if it burns to the ground? What if a bad actor erases everything with a single keystroke? In any case, the data is lost or corrupted.
What a blockchain does is to allow the data held in that database to be spread out among several network nodes at various locations. This not only creates redundancy but also maintains the fidelity of the data stored therein—if somebody tries to alter a record at one instance of the database, the other nodes would not be altered and thus would prevent a bad actor from doing so. If one user tampers with Bitcoin’s record of transactions, all other nodes would cross-reference each other and easily pinpoint the node with the incorrect information. This system helps to establish an exact and transparent order of events. This way, no single node within the network can alter information held within it.
Because of this, the information and history (such as of transactions of a cryptocurrency) are irreversible. Such a record could be a list of transactions (such as with a cryptocurrency), but it also is possible for a blockchain to hold a variety of other information like legal contracts, state identifications, or a company’s product inventory.
To validate new entries or records to a block, a majority of the decentralized network’s computing power would need to agree to it. To prevent bad actors from validating bad transactions or double spends, blockchains are secured by a consensus mechanism such as proof of work (PoW) or proof of stake (PoS). These mechanisms allow for agreement even when no single node is in charge.
Frequently Asked Questions (Q&A) about Blockchain :
What Is a Blockchain in Simple Terms?
Simply put, a blockchain is a shared database or ledger. Pieces of data are stored in data structures known as blocks, and each node of the network has an exact replica of the entire database. Security is ensured since if somebody tries to edit or delete an entry in one copy of the ledger, the majority will not reflect this change and it will be rejected.
How Many Blockchains Are There?
The number of live blockchains is growing every day at an ever-increasing pace. As of 2022, there are more than 10,000 active cryptocurrencies based on blockchain, with several hundred more non-cryptocurrency blockchains.
What’s the Difference Between a Private Blockchain and a Public Blockchain?
A public blockchain, also known as an open or permissionless blockchain, is one where anybody can join the network freely and establish a node. Because of their open nature, these blockchains must be secured with cryptography and a consensus system like proof of work (PoW). A private or permissioned blockchain, on the other hand, requires each node to be approved before joining. Because nodes are considered to be trusted, the layers of security do not need to be as robust.
What Is a Blockchain Platform?
A blockchain platform allows users and developers to create novel uses on top of an existing blockchain infrastructure. One example is Ethereum, which has a native cryptocurrency known as ether (ETH).
But the Ethereum blockchain also allows the creation of smart contracts and programmable tokens used in initial coin offerings (ICOs), and non-fungible tokens (NFTs). These are all built up around the Ethereum infrastructure and secured by nodes on the Ethereum network.
Who Invented Blockchain?
Blockchain technology was first outlined in 1991 by Stuart Haber and W. Scott Stornetta, two mathematicians who wanted to implement a system where document timestamps could not be tampered with. In the late 1990s, Cypherpunk Nick Szabo proposed using a blockchain to secure a digital payments system, known as bit gold (which was never implemented).
The Bottom Line
With many practical applications for the technology already being implemented and explored, blockchain is finally making a name for itself in no small part because of bitcoin and cryptocurrency. As a buzzword on the tongue of every investor in the nation, blockchain stands to make business and government operations more accurate, efficient, secure, and cheap, with fewer middlemen.
As we prepare to head into the third decade of blockchain, it’s no longer a question of if legacy companies will catch on to the technology—it’s a question of when. Today, we see a proliferation of NFTs and the tokenization of assets. The next decades will prove to be an important period of growth for blockchain.
Blockchain is a type of shared database that differs from a typical database in the way that it stores information; blockchains store data in blocks that are then linked together via cryptography.
As new data comes in, it is entered into a fresh block. Once the block is filled with data, it is chained onto the previous block, which makes the data chained together in chronological order.
Different types of information can be stored on a blockchain, but the most common use so far has been as a ledger for transactions.
In Bitcoin’s case, blockchain is used in a decentralized way so that no single 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 viewable to anyone.
Reference : https://www.investopedia.com