Cryptocurrency is a digital or virtual form of currency that uses cryptography for security. It operates on a technology called blockchain, which is a decentralized system that records transactions across multiple computers. The most well-known cryptocurrency is Bitcoin, but there are many others such as Ethereum, Ripple, Litecoin, and more.

Earning money through cryptocurrency can be done in several ways:

1. Mining: Some cryptocurrencies, like Bitcoin, can be mined. Mining involves using powerful computers to solve complex mathematical problems, which validates and secures transactions on the blockchain. Miners are rewarded with newly minted cryptocurrency for their efforts.

2. Trading: Cryptocurrency trading involves buying and selling cryptocurrencies on exchanges with the goal of making a profit. Traders aim to take advantage of price fluctuations and market trends. This approach requires knowledge of market analysis, trading strategies, and risk management.

3. Investing: Investing in cryptocurrencies involves buying and holding them over a longer period in the hopes that their value will increase. This approach is similar to traditional investing and requires careful research and analysis of the cryptocurrency's fundamentals, development team, and market potential.

4. Staking: Some cryptocurrencies use a proof-of-stake (PoS) consensus mechanism, where users can "stake" their coins by holding them in a wallet. By staking, you can help secure the network and, in return, earn rewards in the form of additional cryptocurrency.

5. Participating in Initial Coin Offerings (ICOs) or Token Sales: ICOs are fundraising events where new cryptocurrencies are offered to the public. By participating in an ICO, you can purchase tokens at a discounted price, and if the project succeeds, the value of those tokens may increase.

It's important to note that investing and trading in cryptocurrencies can be highly volatile and risky. Prices can fluctuate significantly, and there is a possibility of losing money. It's advisable to do thorough research, understand the risks involved, and consider seeking professional financial advice before getting involved in cryptocurrency activities.