How do cryptocurrencies like Bitcoin work, and why do people refer to blockchain technology as revolutionary? I’ve read some articles about it, but I still don’t fully understand how transactions through blockchain are secured and why decentralization is such a big deal.
In simple terms, Bitcoin and other cryptocurrencies are digital or virtual currencies that utilize cryptography for security. They operate on a technology called blockchain, which is a decentralized ledger that records all transactions across multiple computers. The decentralization is significant because it makes the data recorded virtually tamper-proof. 

Here's an analogy: Think of blockchain as a digital book of records, where each transaction (called a block) is recorded. Once a block is added to the blockchain, it’s very difficult to change or remove it, because it would require altering every subsequent block, which is almost impossible due to the decentralized nature of the network.

Why is it considered revolutionary? Blockchain technology removes the need for intermediaries like banks in financial transactions, providing more transparency, security, and potentially reducing costs—hence the buzz around it.

Aside from cryptocurrencies, blockchain technology can be applied in other areas such as supply chain management, voting systems, identity verification, and more, which further adds to its significance.