Cryptocurrency is a digital or virtual currency that is secured by cryptography, which makes it nearly impossible to counterfeit or double-spend. Many cryptocurrencies are decentralized networks based on blockchain technology—a distributed ledger enforced by a disparate network of computers. A defining feature of cryptocurrencies is that they are generally not issued by any central authority, rendering them theoretically immune to government interference or manipulation.Cryptocurrency can be exchanged online for goods and services. Many companies have issued their own currencies, often called tokens, and these can be traded specifically for the good or service that the company provides. Cryptocurrencies work using a technology called blockchain, a decentralized technology spread across many computers that manages and records transactions. Part of the claimed appeal of this technology is its security. More than 6,700 different cryptocurrencies are traded publicly, according to CoinMarketCap.com, a market research website. And cryptocurrencies continue to proliferate, raising money through initial coin offerings, or ICOs. The total value of all cryptocurrencies on Feb. 18, 2021, was more than $1.6 trillion, according to CoinMarketCap, and the total value of all bitcoins, the most popular digital currency, was pegged at about $969.6billion. Supporters see cryptocurrencies such as Bitcoin as the currency of the future and profess the fact that cryptocurrency removes central banks from managing the money supply, since over time these banks tend to reduce the value of money via inflation. Other supporters like the technology behind cryptocurrencies, the blockchain, because it’s a decentralized processing and recording system and can be more secure than traditional payment systems. Some speculators like cryptocurrencies because they’re going up in value and have no interest in the currencies’ long-term acceptance as a way to move money. Blockchains have databases at their heart – a collection of information that is stored electronically on a computer system. Information, or data, in databases is typically structured in table format to allow for easier searching and filtering for specific information. Some of the most common cryptocurrencies are Bitcoin, Litecoin, Ethereum, Zcash, Stellar Lumen Sources- Various, Britannica, Wikipedia.