What is the blockchain?
Think of the blockchain as a digital ledger that is completely open for anyone to see. It records transactions, much like a traditional ledger records who has given money to whom, but with a few key differences:
Decentralization
Unlike a bank's ledger, the blockchain isn't stored in one place or controlled by a single entity. It's spread across a network of computers all over the world, making it incredibly difficult to tamper with.
Transparency
Once a transaction is added to the blockchain, it is there for good. Everyone can see it, ensuring everything is transparent and that once something has been written, it can't be changed or erased.
Security
Each transaction is secured using cryptography, which is like a very complex digital puzzle that is extremely hard to break. This keeps all the information safe.
Consensus
For a transaction to be added to the blockchain, multiple computers on the network must agree (or reach consensus) that it is valid. This collective agreement by many different computers adds another layer of security.