Cryptocurrency is a digital or virtual currency that uses cryptography for security and is decentralized, meaning it's not controlled by any government or financial institution. Transactions are recorded on a public ledger called a blockchain, which ensures the integrity and transparency of the network.

Cryptocurrencies have the following characteristics:

1. Digital: Exist only in electronic form.

2. Decentralized: Not controlled by a central authority.

3. Limited supply: Most cryptocurrencies have a capped supply.

4. Fast and global: Transactions are processed quickly, regardless of location.

5. Secure: Use advanced cryptography for secure transactions.

6. Transparent: Transactions are recorded on a public ledger (blockchain).

7. Anonymous: Transactions can be made pseudonymously.

Examples of cryptocurrencies include:

1. Bitcoin (BTC)

2. Ethereum (ETH)

3. Litecoin (LTC)

4. Bitcoin Cash (BCH)

5. Cardano (ADA)

6. Stellar (XLM)

7. EOS

8. Monero (XMR)

9. Dogecoin (DOGE)

10. Many others (over 5,000)