Cryptocurrency is decentralized digital money that’s based on blockchain technology. You may be familiar with the most popular versions, Bitcoin and Ethereum, but there are more than 19,000 different cryptocurrencies in circulation.

How Does Cryptocurrency Work?
A cryptocurrency is a digital, encrypted, and decentralized medium of exchange. Unlike the U.S. Dollar or the Euro, there is no central authority that manages and maintains the value of a cryptocurrency. Instead, these tasks are broadly distributed among a cryptocurrency’s users via the internet.

You can use crypto to buy regular goods and services, although most people invest in cryptocurrencies as they would in other assets, like stocks or precious metals. While cryptocurrency is a novel and exciting asset class, purchasing it can be risky as you must take on a fair amount of research to understand how each system works fully.

Bitcoin was the first cryptocurrency, first outlined in principle by Satoshi Nakamoto in a 2008 paper titled “Bitcoin: A Peer-to-Peer Electronic Cash System.” Nakamoto described the project as “an electronic payment system based on cryptographic proof instead of trust.”

That cryptographic proof comes in the form of transactions that are verified and recorded on a blockchain.

What Is a Blockchain?
A blockchain is an open, distributed ledger that records transactions in code. In practice, it’s a little like a checkbook that’s distributed across countless computers around the world. Transactions are recorded in “blocks” that are then linked together on a “chain” of previous cryptocurrency transactions.

“Imagine a book where you write down everything you spend money on each day,” says Buchi Okoro, CEO and co-founder of African cryptocurrency exchange Quidax. “Each page is similar to a block, and the entire book, a group of pages, is a blockchain.”

With a blockchain, everyone who uses a cryptocurrency has their own copy of this book to create a unified transaction record. Each new transaction as it happens is logged, and every copy of the blockchain is updated simultaneously with the new information, keeping all records identical and accurate.

To prevent fraud, each transaction is checked using a validation technique, such as proof of work or proof of stake.

Proof of Work vs. Proof of Stake
Proof of work and proof of stake are the two most widely used consensus mechanisms to verify transactions before adding them to a blockchain. Verifiers are then rewarded with cryptocurrency for their efforts.

Proof of Work
“Proof of work is a method of verifying transactions on a blockchain in which an algorithm provides a mathematical problem that computers race to solve,” says Simon Oxenham, social media manager at Xcoins.com.

Each participating computer, often referred to as a “miner,” solves a mathematical puzzle that helps verify a group of transactions—referred to as a block—then adds them to the blockchain ledger. The first computer to do so successfully is rewarded with a small amount of cryptocurrency for its efforts. Bitcoin, for example, rewards a miner 6.25 BTC (which is roughly $200,000) for validating a new block.

The race to solve blockchain puzzles can require intense computer power and electricity. That means the miners might barely break even with the crypto they receive for validating transactions after considering the costs of power and computing resources.

Proof of Stake
Some cryptocurrencies use a proof of stake verification method to reduce the amount of power necessary to check transactions. With proof of stake, the number of transactions each person can verify is limited by the amount of cryptocurrency they’re willing to “stake,” or temporarily lock up in a communal safe for the chance to participate in the process.

“It’s almost like bank collateral,” says Okoro. Each person who stakes crypto is eligible to verify transactions, but the odds you’ll be chosen typically increase with the amount you front.

“Because proof of stake removes energy-intensive equation solving, it’s much more efficient than proof of work, allowing for faster verification/confirmation times for transactions,” says Anton Altement, CEO of Osom Finance.

In comparison, for example, the average transaction speed for Bitcoin is at least 10 minutes. Now compare that with Solana, a crypto platform that uses the proof-of-stake mechanism, which averages around 3,000 transactions per second (TPS), making it much faster than the sluggish Bitcoin blockchain.

Also on the horizon is Bitcoin’s biggest rival, Ethereum, is switching fully to a proof-of-stake mechanism. Ethereum estimates its energy usage will decrease by 99.95% once it closes “the final chapter of proof of work on Ethereum.”

The Role of Consensus in Crypto
Both proof of stake and proof of work rely on consensus mechanisms to verify transactions. This means while each uses individual users to verify transactions, each verified transaction must be checked and approved by the majority of ledger holders.

How Can You Mine Cryptocurrency?
Mining is how new units of cryptocurrency are released into the world, generally in exchange for validating transactions. While it’s theoretically possible for the average person to mine cryptocurrency, it’s increasingly difficult in proof-of-work systems, like Bitcoin.

“As the Bitcoin network grows, it gets more complicated, and more processing power is required,” says Spencer Montgomery, founder of Uinta Crypto Consulting. “The average consumer used to be able to do this, but now it’s just too expensive. There are too many people who have optimized their equipment and technology to outcompete.”

Proof-of-work cryptocurrencies also require huge amounts of energy to mine. For example, Bitcoin mining currently consumes electricity at an annualized rate of 127 terawatt-hours (TWh), which exceeds Norway’s entire annual electricity consumption.

While it’s impractical for the average person to earn crypto by mining in a proof of work system, the proof-of-stake model requires less high-powered computing as validators are chosen randomly based on the amount they stake. It does, however, require that you already own a cryptocurrency to participate. (If you have no crypto, you have nothing to stake.)

How Can You Use Cryptocurrency?
While there are a number of goods and services that you can buy with crypto, particularly with Litecoin, Bitcoin or Ethereum, you may also use crypto as an alternative investment option outside of stocks and bonds.

“The best-known crypto, Bitcoin, is a secure, decentralized currency that has become a store of value like gold,” says David Zeiler, a cryptocurrency expert at financial news site Money Morning. “Some people even refer to it as ‘digital gold.’”

How to Use Cryptocurrency for Secure Purchases
Using crypto to make purchases securely depends on what you’re trying to buy.

If you’re trying to make a payment in cryptocurrency, you’ll most likely need a cryptocurrency wallet. One type of wallet is a “hot wallet,” a software program that interacts with the blockchain and allows users to send and receive their stored cryptocurrency.

Remember that transactions are not instantaneous as they must be validated by some form of mechanism.

Best Crypto Exchanges
Cryptocurrencies can be purchased through crypto exchanges, such as Coinbase, Kraken or Gemini. They offer the ability to trade some of the most popular cryptocurrencies, including Bitcoin, Ethereum and Dogecoin. Still, they may also have limitations. You’ll have to check to see if your exchange supports the right crypto pairing you need to make a purchase.

For example, you can use your stash of USD Coin, a crypto stablecoin, to buy Ethereum on Coinbase Exchange.

“It was once fairly difficult but now it’s relatively easy, even for crypto novices,” Zeiler says. “An exchange like Coinbase caters to nontechnical folks. It’s very easy to set up an account there and link it to a bank account.”

Keep an eye out for fees, though, as some of these exchanges charge prohibitively high costs on small crypto purchases.

Ethereum (ETH) is the second most popular cryptocurrency after Bitcoin. Founded by Vitalik Buterin and Gavin Wood in 2015, today Ethereum’s market capitalization represents more than 17% of the $1.2 trillion global crypto market.

There are some distinct differences between Ethereum and the original crypto. Unlike Bitcoin (BTC), Ethereum is intended to be much more than just a medium of exchange or a store of value. Instead, Ethereum is a decentralized computing network built on blockchain technology.

In the crypto’s own words, Ethereum is “a global, decentralized platform for money and new kinds of applications,” with thousands of games and financial apps running on top of the Ethereum blockchain. The crypto is so popular that even other crypto coins run on its network.

Central to Ethereum is its blockchain network. A blockchain is a decentralized, distributed public ledger where transactions are verified and recorded.

It’s distributed in the sense that everyone participating in the Ethereum network holds an identical copy of this ledger, letting them see all past transactions. It’s decentralized in that the network isn’t operated or managed by any centralized entity—instead, it’s managed by all of the distributed ledger holders.

Blockchain transactions use cryptography to keep the network secure and verify transactions.

Ether, the native token on Ethereum, can be used to buy and sell goods and services just like Bitcoin. But what’s unique about Ethereum is that users can build applications that “run” on the blockchain like software “runs” on a computer. These applications can store and transfer personal data or handle complex financial transactions.

Ether and Ethereum: What’s the Difference?
You can use Ether as a digital currency in financial transactions, as an investment or as a store of value. Ethereum is the blockchain network where Ether is held and exchanged. As mentioned above, this network offers a variety of other functions outside of ETH.

“These can be simple movements of funds, but they may also be complex transactions that do anything from exchanging assets to taking out loans to acquiring a piece of digital art,” says Boaz Avital, head of product at Anchorage. The transactions are processed and stored on the Ethereum network.

The Ethereum network can also be used to store data and run decentralized applications. Rather than hosting software on a server owned and operated by Google (GOOGL) or Amazon (AMZN), where the one company controls the data, people can host applications on the Ethereum blockchain. This gives users control over their data and they have open use of the app as there’s no central authority managing everything.

One of the most intriguing use cases involving Ethereum is self-executing contracts, or so-called smart contracts. Like any other contract, two parties agree to deliver goods or services in the future. Unlike conventional contracts, lawyers aren’t necessary: The parties code the agreement on the Ethereum blockchain. Once the contract conditions are met, it self-executes and delivers Ether to the appropriate party.

Ethereum vs. Bitcoin
Bitcoin’s primary use is as a virtual currency and store of value. Ether also works as a virtual currency and store of value. But the decentralized Ethereum network also makes it possible to create and run applications, smart contracts and other transactions on the network. Bitcoin doesn’t offer these functions.

Ethereum also processes transactions more quickly.

“New blocks are validated on the Bitcoin network once every 10 minutes while new blocks are validated on the Ethereum network once every 12 seconds,” says Gary DeWaal, chair of Katten’s financial markets and regulation group. And future developments could speed up Ethereum transactions, even more, he notes.

Last, there is no limit on the number of potential Ether tokens, while Bitcoin will release no more than 21 million coins. Currently, Bitcoin has 19 million coins in circulation.

Ethereum Benefits
Large, existing network. The benefits of Ethereum are a tried-and-true network that has been tested through years of operation and billions of value trading hands. It has a large and committed global community and the largest ecosystem in blockchain and cryptocurrency.
Wide range of functions. Besides being used as a digital currency, Ethereum can also process other financial transactions, execute smart contracts and store data for third-party applications.
Constant innovation. A large community of Ethereum developers is constantly looking for new ways to improve the network and develop new applications. “Because of Ethereum’s popularity, it tends to be the preferred blockchain network for new and exciting (and sometimes risky) decentralized applications,” Avital says.
Avoids intermediaries. Ethereum’s decentralized network promises to let users leave behind third-party intermediaries, like lawyers who write and interpret contracts, banks that are intermediaries in financial transactions or third-party web hosting services.
Ethereum Disadvantages
Rising transaction costs. Ethereum’s growing popularity has led to higher transaction costs. Ethereum transaction fees, also known as “gas,” can fluctuate and be quite costly. That’s great if you’re earning money as a miner but less so if you’re trying to use the network. Unlike Bitcoin, where the network rewards transaction verifiers, Ethereum requires those participating in the transaction to cover the fee.
Potential for crypto inflation. While Ethereum has an annual limit of releasing 18 million Ether per year, there’s no lifetime limit on the potential number of coins. This could mean that as an investment, Ethereum might function more like dollars and may not appreciate as much as Bitcoin, which has a strict lifetime limit on the number of coins.
Steep learning curve for developers. Ethereum can be difficult for developers to pick up as they migrate from centralized processing to decentralized networks.
Ethereum 2.0 Is Coming
Coming soon is Ethereum 2.0, which promises to upgrade Ethereum’s Mainnet to increase scalability. The long-awaited update to the Ethereum blockchain could finally happen this summer, likely in August.

The most significant change with Ethereum 2.0 is that the crypto will switch from a proof-of-work consensus mechanism to proof of stake. This will phase out the need for miners, who run validations on expensive crypto mining equipment and consume a lot of energy.

Staking, which involves locking away a certain amount of cryptocurrency to participate in the transaction verification process, will replace mining to verify Ethereum transactions once the merge is complete.

Ethereum 2.0 is expected to reduce the crypto’s carbon footprint by up to 99.95%.

How to Buy Ethereum
It’s a common misconception among people new to the Ethereum network. You don’t buy Ethereum itself—that’s the network. Instead, you buy Ether and then use it on the Ethereum network. Given Ethereum’s popularity, it’s very easy to buy Ether:

Pick a cryptocurrency exchange. Crypto exchanges and trading platforms are used to buy and sell different cryptocurrencies. Coinbase, Binance.US and Kraken are a few of the larger exchanges. If you are just interested in purchasing the most common coins like Ether and Bitcoin, you could also use an online brokerage like Robinhood or SoFi. Be prepared to pay some amount of trading or processing fees almost universally.
Deposit fiat money. You can deposit cash, like dollars, in your trading platform or link your bank account or debit card to fund purchases of Ether.
Buy Ether. Once you’ve funded your account, you can use the money to purchase Ether at the current Ethereum price along with other assets. Once the coins are in your account, you could hold them, sell them or trade them for other cryptocurrencies in the future. Keep in mind you may incur taxes whenever you sell or trade cryptocurrencies.
Use a wallet. While you could store the Ether in your trading platform’s default digital wallet, this can be a security risk. If someone hacks the exchange, they could easily steal your coins. Another option is to transfer coins you aren’t planning on selling or trading soon into another digital wallet or a cold wallet that’s not connected to the internet for safety.
Should You Buy Ether?
You might consider investing in the Ethereum network for a few reasons, according to DeWaal. “First, it has value and uses as a virtual currency. Second, the Ethereum blockchain could become more attractive when it migrates to the new protocol. And third, as more people utilize Ethereum distributed apps, demand for ETH may increase,” he says.

Besides buying Ether directly, you could also try investing in companies building applications using the Ethereum network. If you’d like help managing your investment, you could also buy into a professional investment fund like the Bitwise Ethereum Fund or Grayscale Ethereum Trust.

Before making any significant investment in Ether or other cryptocurrencies, consider speaking with a financial advisor first about the potential risks. Given the high risk and volatility in this market, make sure it’s money you can afford to lose, even if you believe in Ethereum’s potential.

Bitcoin is a digital currency which operates free of any central control or the oversight of banks or governments. Instead it relies on peer-to-peer software and cryptography.

A public ledger records all bitcoin transactions and copies are held on servers around the world. Anyone with a spare computer can set up one of these servers, known as a node. Consensus on who owns which coins is reached cryptographically across these nodes rather than relying on a central source of trust like a bank.

Every transaction is publicly broadcast to the network and shared from node to node. Every ten minutes or so these transactions are collected together by miners into a group called a block and added permanently to the blockchain. This is the definitive account book of bitcoin.

In much the same way you would keep traditional coins in a physical wallet, virtual currencies are held in digital wallets and can be accessed from client software or a range of online and hardware tools.

Bitcoins can currently be subdivided by seven decimal places: a thousandth of a bitcoin is known as a milli and a hundred millionth of a bitcoin is known as a satoshi.

In truth there is no such thing as a bitcoin or a wallet, just agreement among the network about ownership of a coin. A private key is used to prove ownership of funds to the network when making a transaction. A person could simply memorise their private key and need nothing else to retrieve or spend their virtual cash, a concept which is known as a “brain wallet”.

Can bitcoin be converted to cash?
Bitcoin can be exchanged for cash just like any asset. There are numerous cryptocurrency exchanges online where people can do this but transactions can also be carried out in person or over any communications platform, allowing even small businesses to accept bitcoin. There is no official mechanism built into bitcoin to convert to another currency.

Nothing inherently valuable underpins the bitcoin network. But this is true for many of the world’s most stable national currencies since leaving the gold standard, such as the US dollar and UK pound.

What is the purpose of bitcoin?
Bitcoin was created as a way for people to send money over the internet. The digital currency was intended to provide an alternative payment system that would operate free of central control but otherwise be used just like traditional currencies.

Are bitcoins safe?
The cryptography behind bitcoin is based on the SHA-256 algorithm designed by the US National Security Agency. Cracking this is, for all intents and purposes, impossible as there are more possible private keys that would have to be tested (2256) than there are atoms in the universe (estimated to be somewhere between 1078 to 1082).

There have been several high profile cases of bitcoin exchanges being hacked and funds being stolen, but these services invariably stored the digital currency on behalf of customers. What was hacked in these cases was the website and not the bitcoin network.

In theory if an attacker could control more than half of all the bitcoin nodes in existence then they could create a consensus that they owned all bitcoin, and embed that into the blockchain. But as the number of nodes grows this becomes less practical.

A realistic problem is that bitcoin operates without any central authority. Because of this, anyone making an error with a transaction on their wallet has no recourse. If you accidentally send bitcoins to the wrong person or lose your password there is nobody to turn to.

Of course, the eventual arrival of practical quantum computing could break it all. Much cryptography relies on mathematical calculations that are extremely hard for current computers to do, but quantum computers work very differently and may be able to execute them in a fraction of a second.

What is bitcoin mining?
Mining is the process that maintains the bitcoin network and also how new coins are brought into existence.

All transactions are publicly broadcast on the network and miners bundle large collections of transactions together into blocks by completing a cryptographic calculation that’s extremely hard to generate but very easy to verify. The first miner to solve the next block broadcasts it to the network and if proven correct is added to the blockchain. That miner is then rewarded with an amount of newly created bitcoin.

Inherent in the bitcoin software is a hard limit of 21 million coins. There will never be more than that in existence. The total number of coins will be in circulation by 2140. Roughly every four years the software makes it twice as hard to mine bitcoin by reducing the size of the rewards.

When bitcoin was first launched it was possible to almost instantaneously mine a coin using even a basic computer. Now it requires rooms full of powerful equipment, often high-end graphics cards that are adept at crunching through the calculations, which when combined with a volatile bitcoin price can sometimes make mining more expensive than it is worth.

Miners also choose which transactions to bundle into a block, so fees of a varying amount are added by the sender as an incentive. Once all coins have been mined, these fees will continue as an incentive for mining to continue. This is needed as it provides the infrastructure of the Bitcoin network.

Who invented bitcoin?
In 2008 the domain name .org was bought and an academic white paper titled Bitcoin: A Peer-to-Peer Electronic Cash System was uploaded. It set out the theory and design of a system for a digital currency free of control from any organisation or government.

The author, going by the name Satoshi Nakamoto, wrote: “The root problem with conventional currencies is all the trust that’s required to make it work. The central bank must be trusted not to debase the currency, but the history of fiat currencies is full of breaches of that trust.”

The following year the software described in the paper was finished and released publicly, launching the bitcoin network on 9 January 2009.

Nakamoto continued working on the project with various developers until 2010 when he or she withdrew from the project and left it to its own devices. The real identity of Nakamoto has never been revealed and they have not made any public statement in years.

Now the software is open source, meaning that anyone can view, use or contribute to the code for free. Many companies and organisations work to improve the software, including MIT.

What are the problems with bitcoin?
There have been several criticisms of bitcoin, including that the mining system is enormously energy hungry. The University of Cambridge has an online calculator that tracks energy consumption and at the beginning of 2021 it was estimated to use over 100 terawatt hours annually. For perspective, in 2016 the United Kingdom used 304 terawatt hours in total.

The cryptocurrency has also been linked to criminality, with critics pointing out to it being a perfect way to make black market transactions. In reality, cash has provided this function for centuries, and the public ledger of bitcoin may actually be a tool for law enforcement.