What Is Cryptocurrency, Really?

Cryptocurrency is a form of digital money built on a blockchain: a shared, continuously growing digital record of transactions, maintained by a network of computers instead of a single bank or government. Bitcoin, launched in 2009, was the first, and thousands of others have followed since.

The key difference from a traditional bank account is who's in control. A bank maintains its own private record of your balance, and can freeze or reverse transactions. A blockchain's record is shared across a distributed network, with no single company or government in charge of it — that's what people mean by decentralization, covered in more depth next level.

Cryptocurrency is built on a ____: a shared, continuously growing digital record maintained by a network instead of one bank.

It's worth separating two different questions early: whether the underlying technology is genuinely interesting (it is, and this track explores why) and whether any specific cryptocurrency is a good investment for you (a much harder, more personal question, covered honestly in later levels). Plenty of interesting technology has still made for a poor short-term investment, and vice versa.

What is the key difference between how a bank tracks your balance and how a blockchain works?

Whether a technology is genuinely interesting and whether a specific cryptocurrency is a good investment are the exact same question.