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What is Blockchain?
It’s one of the most puzzling questions we find ourselves trying to answer when first discovering cryptocurrencies. So getting blockchain explained is essential.
Ready? Here’s what is blockchain in simple words:

The main purpose of the blockchain is to allow fast, secure and transparent peer-to-peer transactions. It is a trusted, decentralized network that allows for the transfer of digital values such as currency and data.

Now, as we’re all newbies here. Here’s the blockchain for dummies:

Imagine the blockchain as a digital database, just like an Excel spreadsheet.
This database is typically shared across a large network containing many computers (known as “nodes”) and it is completely public. I say “typically” because it can technically be formed by any number of nodes. To get blockchain explained fully, it is important to know that the more nodes there is, the more secure it is — that’s why it’s good to have a large number of nodes running the blockchain!
Every time the network makes an update to the database, it is automatically updated and downloaded to every computer on the network.
Blockchain technology is secured with cryptographic techniques, making it near impossible for hackers to make changes to it. The only way to make changes would be to hack more than half of the nodes in the blockchain, which again, is why it is more secure to have more nodes/computers running the blockchain.
That’s your blockchain explained in simple words. So, now when someone asks you “what is blockchain?”, you have two strong answers to choose from.

How Does Blockchain Work in the Case of Bitcoin?
Bitcoin was the first cryptocurrency to use blockchain technology. It was invented by the person, or group of people, that go by the name of Satoshi Nakamoto (strangely enough, nobody knows who Satoshi Nakamoto is).

The sole purpose of Bitcoin is to act as a store of value. It allows for peer-to-peer transactions that do not need a third party, such as PayPal or a bank.

Getting Bitcoin blockchain explained is essential to understanding how blockchain works. The Bitcoin blockchain is a database (known as a “ledger”) that consists only of Bitcoin transaction records. There is no central location that holds the database, instead, it is shared across a huge network of computers. So, for new transactions to be added to the database, the nodes must agree that the transaction is real and valid.

Blockchain explained: a bank.

This group agreement is also known as a “consensus”. It occurs during the process of mining.

Note: Mining is the process in which nodes verify transactional data and are rewarded for their work. It covers their running costs (electricity and maintenance etc.) and a small profit too for providing their services. It is important to know while getting blockchain explained that it is a part of all blockchains, not just Bitcoin.
Once the nodes agree that the transaction is real, it is then added to a “block” (which is why it is called a blockchain) and is placed below the previous block of transactions in the ledger.

For a transaction to be valid, the computers on the network must confirm that:

(1) The account holds the amount of Bitcoin that the user wants to send.
(2) The amount hasn’t already been sent to someone else.

For example, let’s imagine that Tom tries to send $10 of Bitcoin to Ben. Tom only has $5 worth of Bitcoin in his wallet. Because Tom doesn’t have the funds to send $10 to Ben, this transaction would not be valid. The transaction will not be added to the ledger.

Blockchain explained: Bitcoins on a computer chip.

This means that nobody can ever spend the same money twice! This can often be a big problem for standard banks and payment systems.

A Simple Example to get Blockchain Explained Better:

Let’s compare how data is stored and shared in standard (non-blockchain) systems to how it is stored and shared in a blockchain system.

The way that traditional (non-blockchain) ledgers work is very similar to the way you would share a Microsoft Word document with your friend:

While you are editing the document, your friend is locked out and cannot make changes.
Once you have finished making your changes, you send it to your friend to edit it further.
Now while your friend is editing the document, you are locked out and cannot make changes until they are finished and send it back to you.
In a blockchain system, however, all users can view the changes while they are being made.

Blockchain explained: a blockchain.

The data is accessible in a secure and shared environment, instead of being locked to one company or person at a time (at the risk of losing the data). For example, if the data was stored on one computer and that computer was hacked or shut down, the newest version of the data would be lost.

Now, to get blockchain explained: with the blockchain, the data is stored on all the computers/nodes that run it. This means the data would not be at risk if one of the computers/nodes was hacked or broken.

As you can see, blockchain technology does not just benefit cryptocurrencies. It benefits many different industries. Imagine the amounts of legal, health, accounts and customer data, etc. that should be used this way.

This is just one of the many advantages of blockchain technology! Now, let’s look at some of the others.