Blockchain is a technology used to store information securely, transparently, and decentralized.
It can be imagined as a giant digital book that is distributed among many people (computers) and keeps a history of data, such as transactions, in such a way that no one can change it once registered.
How it works:
Blocks:
Information is grouped into blocks (like pages of a book). Each block contains data, such as transactions, a unique identifier (hash), and is linked to the previous block.
Chain:
The blocks are connected in order, creating a continuous chain, hence the name "blockchain."
Decentralization:
Instead of being in one place (like a bank server), the blockchain is copied across thousands of computers (nodes) around the world. This makes it very difficult to hack.
Immutability:
Once the information is on the chain, it cannot be changed or deleted. If someone tries to modify a block, the system detects it and rejects the changes.
Transparency and Security:
All participants in the network can see the contents of the chain, but the information is encrypted to protect privacy.
EASY Example:
Imagine you have a group of friends and everyone writes down in their notebooks every time someone lends or receives money.
If someone tries to change their entry, to improve their income or hide something, others will check their notebooks and detect the "error" to correct it so that there are no incorrect data in anyone's notebook.
In this way, trust among the entire group is not necessary since there are records that are above all that and the calculation is safe, controlled, measured, and reliable.
The blockchain does something similar, but using technology and mathematics.
Common uses:
Cryptocurrencies: Like Bitcoin and Ethereum, which use blockchain to record transactions.
Smart contracts: Programs that run automatically when certain conditions are met.
Product tracking: To know the origin of food, medicine, or any goods.
* This is a revolutionary technology because it eliminates the need for intermediaries, such as banks, and makes processes more secure and transparent *
