What is a blockchain?

A blockchain may seem like a complicated technical topic, and that is not wholly untrue, but it’s still possible for anyone to understand the main idea of how a blockchain works. We just learned about ledgers, which is the basis for understanding blockchain.
At its core, a blockchain is a decentralized ledger. It contains all of the transactions in a digital form, and is managed by a lot of different people. When talking about blockchain, the people who are checking the transactions on the blockchain are called validators.
Let’s examine in simple terms what happens in a blockchain when someone makes a transaction.
Let’s say you send money to your friend. All of the information about that transmission (your wallet address, your friend’s wallet address, the cryptocurrency, the amount, etc.) gets recorded on a blockchain and checked by validators. Validators maintain the ledger following consensus algorithms that may differ from one blockchain to another. In our example, you can imagine a validator checking your transaction information and running the math. So does the next validator, and the next, and so on. They’re all checking each other to make sure that the information in the blockchain is correct. If there’s an error or someone wants to try something sneaky, it will be corrected because everyone is checking everyone else.
To learn more about consensus mechanisms, watch this short video:
Of course, validators don’t work for free, which is why “gas fees” are charged with each transaction. But more on that later.
When you link all of these validated transactions of a decentralized ledger together, you get a blockchain. Not only are these transactions highly accurate, with ownership shared among many individuals, but the blockchain is also public and transparent. Anyone can go and look at the transactions happening there.
Maybe you’re not as interested in those aspects and you just want to send money and pay for the things you want. Blockchains have benefits for you too. Since there’s no middleman, you don’t have to wait for the banks and payment providers to process your transactions. They are fast—almost instantaneous—to anywhere in the world. Crypto never sleeps. You can process your transactions 24/7 on every day of the year. Furthermore, without the middleman, you also save a lot on traditional banking fees. You’re only paying the validators to make a peer-to-peer transaction.
Now that you have the basics on centralized ledgers, decentralized ledgers, and the blockchain, let’s talk about the cryptocurrencies on those blockchains.