What is a cryptocurrency?
Cryptocurrency in plain English: digital units on a shared ledger, coins vs. tokens, and what gives them value.
A cryptocurrency is a digital unit of value that lives on a shared computer record called a blockchain. There are no paper notes and no metal coins. What you "own" is an entry in that record saying a certain amount belongs to an address you control.
The word "crypto" comes from cryptography, the math used to keep information secure. Cryptography lets you prove that you are allowed to move your units without showing anyone your secret password.
Money vs. crypto
Ordinary money, like US dollars or euros, is called fiat money. A government declares it legal tender and a central bank manages how much exists. Your bank keeps the record of how much you have.
With most cryptocurrencies, there is no central bank and no single company keeping the record. Thousands of computers around the world each hold a copy of the ledger and follow the same rules to update it. That is why people call crypto decentralized.
Coins vs. tokens
You will hear two words used a lot:
- Coin: the native unit of its own blockchain. Bitcoin (BTC) is the coin of the Bitcoin network. Ether (ETH) is the coin of Ethereum. Coins are usually needed to pay network fees.
- Token: a unit created on top of an existing blockchain by a program. Thousands of tokens run on Ethereum, for example. A token can represent almost anything: a dollar-pegged unit, a voting right in a project, or simply a joke.
People often say "coins" for everything. That is fine in conversation, but the difference matters when you research a project.
Maria sends 0.01 BTC to her friend. No bank is involved. Her wallet signs the transfer with her secret key, the network checks the signature, and within roughly 10 minutes to an hour the shared ledger shows 0.01 BTC less at Maria's address and 0.01 BTC more at her friend's address.
What gives crypto value?
A cryptocurrency is worth only what other people are willing to pay for it. There is no government promise behind it and usually no company profit flowing to holders. Some people value it as a scarce digital asset, some for its use in apps, and many simply because they hope the price will rise.
This is the most important beginner idea: nothing guarantees that a crypto asset keeps its value. Prices can rise a lot, and they can also fall to almost zero.
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