Imagine you have a magical notebook where all the pages are indestructible and cannot be erased. Every time you write something in this notebook, everyone in the world receives an exact copy of that page. Sounds amazing, doesn’t it? This magical notebook is, quite simply, what we call a blockchain.
Now, let's better understand what this means and how it works.
What does "blockchain" mean?
The word "blockchain" comes from English and means "chain of blocks". Think of it as a chain of connected blocks, where each block is like a page in the magic notebook we mentioned earlier.
Each block stores:
1. Information - Such as transactions, data or records (in the case of cryptocurrencies, who sent how much money to whom).
2. A "security stamp" - A special code called a hash, which ensures that the block cannot be changed.
3. A link to the previous block - This way, the blocks are connected in a sequence, forming the "chain".
Why is blockchain special?
1. It’s secure: When something is recorded on the blockchain, it is verified by multiple people (or computers, in this case) and cannot be deleted or altered. This prevents fraud.
2. It’s transparent: Everyone can see what’s recorded on the blockchain. For example, if you send money using Bitcoin, anyone can see that the transaction happened, but no one knows who you are, ensuring your privacy.
3. It’s decentralized: There is no “owner” or place where the blockchain is stored. It is spread across the world, on thousands of computers. This means that no company or government can control or shut down the blockchain.
O Bitcoin e o blockchain
Now let's see how blockchain works using Bitcoin as an example.
Bitcoin was the first cryptocurrency to use blockchain technology, created in 2009 by someone (or a group of people) called Satoshi Nakamoto.
Imagine you want to send 1 Bitcoin to a friend. Here's what happens:
1. You make the transaction: You send 1 Bitcoin to your friend's address (like an account number). This transaction is like a note that will be written in the "magic notebook".
2. The transaction is verified: Before it can be accepted, this transaction needs to be confirmed by multiple people (or computers) on the Bitcoin network. These computers verify that you actually have 1 Bitcoin to send and that everything is correct.
3. The transaction enters a block: After being verified, your transaction is placed together with others in a "block". This block is like a page in a notebook.
4. The block is added to the chain: Once the block is ready, it is connected to the previous block in the chain (blockchain). And that's it! Now the transaction is recorded forever and no one can change it.
Why not trust blockchain?
Unlike a bank, where you rely on a company to handle your money, blockchain is maintained by thousands of people around the world. They all verify the information at the same time, which makes the system very secure and reliable.
Furthermore:
Each block has its own unique code (hash), and if someone tries to change anything, the code will not match. This indicates an attempted fraud.
Since the network is spread out (decentralized), even if one computer is turned off, the others continue to function.
Summary
Blockchain is like a magic notebook, where everything that is recorded is recorded forever, securely, transparently and without the need for intermediaries like banks. Bitcoin is just one example of how blockchain can be used, but this technology has the potential to transform other areas, such as contracts, healthcare and even elections.
Now that you know the basics of blockchain, it's easier to understand how it's at the heart of many cryptocurrencies and why it's such a groundbreaking technology!
