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Blockchain

A shared, tamper-proof record that anyone can verify

3 quiz questions

Blockchain

Imagine a notebook that everyone can see and write in, but no one can secretly change or erase.

Every time someone adds a note, everyone else checks that it's correct. Once something is written down, it stays there forever, visible to all.

That's the basic idea behind blockchain: a shared, tamper-proof record that anyone can verify.

Normally, when we exchange money, goods, or information online, we rely on trusted companies to keep track of it, like payment processors, social media platforms, or marketplaces. But trusting a single group comes with risks: mistakes, censorship, delays, or unfair rules.

Blockchain offers a different approach.

It's a public record that lives across thousands of computers, not one central server. No single person controls it. Updates are proposed, checked by the network, and locked in once everyone agrees.

Here's how it works:

First, someone wants to add a new record, like sending money or confirming a transaction.
Second, the update is shared with the network.
Next, the network checks if it follows the rules.
Finally, once enough computers agree, the update is grouped into a "block" and added to the chain of past records.

Because the system runs on shared rules, not trust in any one person, it's called trustless. You don't need to trust strangers — you trust the math and the network.

What does trustless mean? Trustless doesn't mean the lack of trust; it means you can rely on the system itself, not any single person. Every action is recorded transparently, and everyone follows the same rules — without needing permission or blind trust.

Today, people use blockchains for all sorts of things:

Storing digital money like Bitcoin.
Tracking supply chains for food, clothing, or medicine.
Running global communities and projects that anyone can join.
Creating automatic agreements (called "smart contracts") that carry out actions once conditions are met.

As an example, let's imagine a few musicians around the world wanting to release a song together. Instead of signing complicated deals or relying on a big company, they upload the song to a blockchain system. Every time the song is streamed or bought, the payment automatically gets split and sent straight to each artist's digital wallet — instantly, fairly, and without a middleman.

So, to summarize, blockchain is a way to store information openly, securely, and permanently. It's a tool for creating transparent systems where people can cooperate, even if they don't know or fully trust each other.

Additional Resources

IBM — A simple and clear intro to blockchain basicsConsenSys — A blockchain glossary for beginners