Cryptocurrency refers to a form of digital or virtual currency that uses cryptography to secure transactions, control the creation of new units, and verify the transfer of assets. Unlike traditional currencies (such as the euro or the dollar), cryptocurrencies are not issued by a central authority, such as a central bank, which gives them a decentralized nature.

### Main characteristics of cryptocurrencies:

1. **Decentralization**: Cryptocurrencies operate on decentralized networks, often based on blockchain technology. This means that no single entity controls the network.

2. **Security**: Cryptography is used to secure transactions and control the creation of new currency units. This reduces the risk of fraud and manipulation.

3. **Transparency**: All transactions made in cryptocurrencies are recorded on a blockchain, a kind of public digital ledger, allowing anyone to verify transactions.

4. **Anonymity**: Although transactions are transparent, the identities of users are often protected, offering a certain level of anonymity.

5. **Accessibility**: Cryptocurrencies can be sent and received by anyone with internet access, enabling global transactions without intermediaries.

### Examples of cryptocurrencies:

- **Bitcoin (BTC)**: The first and most well-known cryptocurrency, launched in 2009 by a person or group using the pseudonym Satoshi Nakamoto.

- **Ethereum (ETH)**: A platform that allows the creation of smart contracts and decentralized applications (DApps).

- **Ripple (XRP)**: Designed to facilitate fast and low-cost payments between different currencies.

- **Litecoin (LTC)**: Often considered the silver to Bitcoin's gold, popular for its faster transactions.