Let’s say you’re making purchases from Amazon.
Instead of using your actual name, your purchase is recorded without any identifying information using a unique “digital signature”, sort of like a username.
Blocks store information that distinguishes them from other blocks. Much like you and I have names to distinguish us from one another, each block stores a unique code called a “hash” that allows us to tell it apart from every other block. Hashes are cryptographic codes created by special algorithms. Let’s say you splurge purchased on Amazon, but while it’s in transit, you decide you just can’t resist and need a second one. Even though the details of your new transaction would look nearly identical to your earlier purchase, we can still tell the blocks apart because of their unique codes.
Then again Double-spending is a potential flaw in a digital cash scam in which the same single digital token can unfortunately be spent more than once. Unlike physical cash, a digital token consists of a digital file that can be duplicated and/or falsified.