Think about the cash in your wallet. If you trade your $10 bill for a friend's $10 bill, you both still have $10. Nothing has really changed. Your bill is interchangeable with theirs. This property is called fungibility.

Now, imagine you own the original Mona Lisa painting. There is only one in the world. You couldn't trade it for another painting and still have the exact same thing. The Mona Lisa is unique and irreplaceable. It's non-fungible.

An NFT, or Non-Fungible Token, is basically a digital certificate of ownership for a unique item, whether that item is digital or physical. It's a one-of-a-kind token that says, "This specific digital file belongs to this person." This proof of ownership is recorded publicly and permanently.

This uniqueness is the core idea behind NFTs. Each NFT has distinct information that makes it different from any other NFT, much like a concert ticket has a specific seat number, date, and venue that makes it unique.

It's a common mistake to lump NFTs and cryptocurrencies together, but they serve very different purposes. The key difference goes back to that idea of fungibility.

Cryptocurrencies, like Bitcoin or Ethereum, are fungible. One Bitcoin is worth the same as any other Bitcoin, just like our $10 bill example. They are designed to be a medium of exchange, a digital form of money.

NFTs, on the other hand, are all about uniqueness. Each one is a distinct asset representing ownership of something specific. You can't exchange one NFT for another and have the same item, because no two are identical.

So where is this proof of ownership recorded? It's stored on a blockchain. A blockchain is a type of shared digital ledger that is distributed across a network of computers. Think of it as a community's public record book.

When someone creates or sells an NFT, that transaction is recorded as a "block" of data. This block is then cryptographically linked to the previous block, creating a chain of records. Because this chain is shared and verified by many computers, it's extremely difficult to alter or tamper with. This is what makes NFT ownership secure, transparent, and easily verifiable by anyone.

This permanent and public record means you don't need a central authority like a bank or a gallery to prove you own something. The blockchain itself is the proof.

Now that we have a handle on what NFTs are and the technology that powers them, we can start to look at how they're used. Let's check your understanding first.