Blockchain is a data storage technology that works like a large digital ledger. It is designed to be tamper-proof and accessible to all participants in the system.

In simple terms:

1. Blockchain: Data in a blockchain is stored in blocks that are linked together in chronological order. Each new block is added to the end of the chain.

2. Decentralization: The blockchain is not stored on a single server or computer. Instead, it is distributed among many computers (nodes), making it resistant to failures and hacks.

3. Transparency and security: All records in the blockchain are visible to network participants, but they cannot be changed. To make changes, the consent of the majority of participants is required.

Example:

Imagine that you have a notebook in which you write down all the transactions with your friends. Every time you add a new entry, you show it to everyone, and everyone agrees that it is correct. No one can secretly change old records because everyone has a copy of the notebook.

This is the principle of blockchain!