What are smart contracts?

Smart contracts are the foundational technology behind NFTs

Smart contracts use “if that, then this” logic to track the ownership of NFTs and record when they are bought and sold on the blockchain.

The blockchain offers tantalizing possibilities for future use

Think of blockchains as a running list of information, where new details are added to the running chain as discrete "blocks." With crypto, the information contained within each block could be virtually anything, providing flexibility for uses in commerce, legal filings, healthcare records, and more.

Watch an expert explain blockchain technology to five different people: a child, a teen, a college student, a grad student, and a fellow expert.

Ethereum is a blockchain-powered platform for building decentralized software and apps

Among crypto enthusiasts, ethereum is known for the cryptocurrency it uses to facilitate transactions: ether, or ETH. It's often compared to an app store. The underpinnings of ethereum's blockchain include dApps, which operate using automated scripts called "smart contracts."

The industries ripe for disruption by blockchain and cryptocurrencies

Blockchain—what is it good for? Lots of things, it would seem. Peruse this guide from The Motley Fool site and learn about different applications and use cases for blockchain technology. Financial exchanges, real estate, insurance, voting, an gambling are just a few of the 15 applications discussed here.

The benefits of cryptocurrency and blockchain technology

At the root of cryptocurrencies' allure is blockchain technology, an innovation bringing profound transformations to industries, especially the financial industry. This simple article breaks down the difference between cryptocurrencies and blockchain as well as the benefits of each.

What is a smart city?

The internet of things and automation are two of the technologies used in smart cities. Learn about the technologies making cities more human-centric in this three-minute read.

Ethereum is a blockchain-powered operating system known for its cryptocurrency, ether

Ethereum's underlying blockchain allows developers to build decentralized applications (dApps) that leverage smart contracts to seamlessly run decentralized financial tools (crypto wallets, exchanges, marketplaces, and more), along with Web3 concepts like non-fungible tokens.

Using cryptocurrency to turn traditional financial arrangements on their head

Cryptocurrency is poised to drastically change everything in the financial world, including financial arrangements. Decentralized finance makes it easier for virtually anyone to take advantage of financial markets without the need for a bank. However, there are new risks involved as well. Professor of Legal Studies and Business Ethics Kevin Werbach, an expert on Bitcoin and blockchains discusses it all in detail in The Conversation.

Ledgers—what are they good for?

It might seem strange that a ledger—a dull and practical document associated mainly with accounting—would be described as a revolutionary technology. But the blockchain matters because ledgers matter. Read (or listen to) this 14 minute breakdown on why ledgers matter.

See how the concept of verification and addition to the blockchain works in real time.

Every transaction made via bitcoin is recorded on its blockchain—the decentralized, distributed ledger that provides a permanent and transparent record of the currency's entire history. While that may sound abstract, the technology allows anyone to monitor and confirm each of the transactions.

Decentralized applications are blockchain-based and run without a central authority

These apps use smart contracts to automatically execute functions, ensuring security, transparency, and censorship resistance. Built on platforms like Ethereum, Solana, and Binance Smart Chain, DApps power DeFi, NFTs, gaming, and social media, offering users control over their data and assets.

A simple visual explanation of how blockchains work

Blockchains are decentralized, distributed, and digital methods to record transactions and prevent alterations and tampering of the record. That's a simplified definition. This easy-to-understand six-minute video further and better explains what blockchains are and how they work using colorful illustrations and clear, concise clarifications on their processes and what makes them so special.

Bitcoin and ethereum are decentralized cryptocurrencies with different functions

Bitcoin, launched in 2009, is primarily a digital currency and store of value with a fixed supply. Ethereum, introduced in 2015, enables smart contracts and decentralized apps, offering more flexibility.

Bitcoin explained and made simple

Bitcoin, the most popular and well-known example of a cryptocurrency, came on the scene around 2010, with its evangelists proclaiming it would eventually displace government-backed traditional cash. While the concept of a digital currency may seem straightforward, the details can be deceptively simple. This quick video overview provides the foundation for a deeper dive into the world of decentralized currency.

A visual guide to how bitcoin transactions work and rely on cryptography

The "crypto-" in cryptocurrencies like bitcoin refers to the mathematical functions that generate pairs of public and private keys and encrypt data in blocks. When combined, these systems secure transactions on the network, verify digital asset and token transfers, and contribute to end-user anonymity.

What is blockchain? A visual explanation from a Stanford professor

Stanford professor Dan Boneh teaches "Blockchain Primitives: Cryptography and Consensus," providing an introduction to the cryptographic foundation of blockchains and how developers can use them to build new types of applications.

Learn about Web3 and how it differs from past versions of the internet

Web3 is the idea of a new, decentralized internet built on blockchain technology. It aims to shift control from centralized entities like big tech companies to users through distributed ledgers and smart contracts. Key components include cryptocurrencies, NFTs, and decentralized autonomous organizations (DAOs) that operate without a central authority. Web3 promises more user privacy, ownership, and control over data and digital assets.

The future of the internet

Blockchain? Crypto? NFTs? Oh my. Gilles DC provides a simple breakdown of what Web3 is, what it involves, its connection with web currencies, and how you can begin your own explorations of this brave new world. Gilles promises to describe Web3 in one take, explain how the reader can take advantage of it, and how blockchain might build a better society as a result.

Solana is a blockchain designed for fast, scalable, low-cost transactions

Solana uses a unique Proof-of-History and Proof-of-Stake hybrid to process thousands of transactions per second. Solana supports a wide range of Web3 applications, offering an alternative to Ethereum with lower fees and faster speeds. Its native cryptocurrency, SOL, is used for transactions, staking, and governance.

Cryptocurrency acts as a store of value

Traditional money, dating back to its first known uses in ancient Babylonia, has many uses—it reduces friction in transactions by providing a common denominator of value (unit of account), acts as a single item accepted by many vendors (medium of exchange), and holds wealth as a store of value.

Why blockchain applications are worth investing and building

Chris Dixon is a general partner at Andreessen Horowitz. In this hourlong podcast episode, Dixon shares his overall thesis for investing in the cryptocurrency space, the opportunities and limitations of blockchain applications, and why this is the most interesting area for investing and building over the next 10 years.

Who accepts bitcoin payments in 2025?

Bitcoin and other cryptocurrencies are used primarily as stores of value or speculative assets, and less likely to be used to purchase goods and services. Advocates for the currency say as an increasing number of retailers accept bitcoin, average holders will begin to treat the currency more like traditional money.

Stablecoins now transfer more value than Visa or Mastercard.

Because stablecoins operate on public blockchains, transfers can occur nearly instantly without intermediaries, unlike traditional credit card networks. This has fueled stablecoins' adoption within the crypto world and in cross-border payments. Stablecoin transfer volume rose from about $3B in 2018 to roughly $18T in 2024, overtaking Visa's roughly $16T and Mastercard's $10T.

A definitive guide to crypto and blockchain

The concept of cryptocurrency emerged more than a decade ago, with a famous whitepaper on bitcoin. To fully understand the rise of bitcoin, Bloomberg’s Matt Levine developed this comprehensive four-part series exploring the broader crypto and blockchain ecosystems, where they came from and how they work (subscription required).

Futures contracts—which are agreements to buy or sell a standardized asset at a specific future time—are the primary way commodities are bought and sold.

Bitcoin, the oldest and most popular cryptocurrency, is a digital cash alternative introduced in 2009 that rapidly grew in popularity and now boasts a global user base.

A look at nodes and miners in managing bitcoin transactions

Each time a transaction involving bitcoin is carried out, the information must be relayed and recorded onto the currency’s blockchain. Multiple steps are involved, including the passage of the transaction to various nodes and miners who comprise multiple layers of verification and validation. See an illustrated guide to how these two crucial features of bitcoin processing work here.

NFTs can be minted using an online marketplace or directly on the blockchain

Minting, or creating, an NFT is how NFTs are added to the blockchain. The process can be simplified by using a popular marketplace.

Trusts are estate planning tools

They’re used as a way to designate assets to beneficiaries while skirting certain taxes and maintaining one’s privacy. They can hold a wide range of assets, including cash, real estate, stocks, businesses, and more.

Only 21 million bitcoin will ever be created—what happens then?

Bitcoin is a popular cryptocurrency with a finite supply, and the issuance of new bitcoins is currently offered as a reward for verifying the transactions on the blockchain. Experts say the currency won't reach its limit until the year 2140, and miners may ultimately rely on transaction fees.

The Chain Reaction podcast: The latest in bitcoin and blockchain developments

There are constantly new tokens, DeFi projects, NFT collections, and DAOs being launched, but how can you make sense of everything going on in the crypto space? TechCrunch senior crypto reporter Jacquelyn Melinek explores the impact of crypto on finance, art, web3, and society as a whole. One the best resources to keep up with actual—meaning, beyond the hype—developments in the world of bitcoin and blockchain.

Top Ethereum dApps

Thousands of decentralized apps (dApps) run on Ethereum, including marketplaces, financial platforms, and social networks. Top apps include Uniswap, a decentralized exchange for buying and selling cryptocurrency, and OpenSea, the biggest marketplace for buying and selling non-fungible tokens (NFTs). New apps are built on Ethereum all the time, facilitating billions of dollars worth of transactions. Explore the biggest ones here.

Bitcoin mining validates/adds bitcoin transactions onto the blockchain

Mining, done by a decentralized network of actors, is incredibly energy intensive, making the award of bitcoins a major incentive.

Dubai and Barcelona are examples of smart cities

By integrating technology into public transit, utilities, and other municipal systems, these cities aim to reduce costs and enhance the quality of life for their residents. Some of these technologies include adaptive lighting, parking sensors, and underground waste systems.

Many bitcoin enthusiasts have compared the cryptocurrency to digital gold

Gold is valued for its stability and reliability, serving as a hedge against inflation and economic uncertainty. Bitcoin shares both of these characteristics, but also provides near-instant liquidity and isn’t subject to government regulation.

Crypto exchanges are online platforms to buy, sell, and exchange cryptocurrencies

Crypto exchanges have grown alongside and fueled the boom in digital currencies. Popular exchanges like Coinbase, Kraken, and Binance each have separate features, fee structures, and more. You can learn how to begin with the platforms, how to carry out research, and when to be aware of the associated risks.

Vitalik Buterin’s current thoughts on Ethereum

Vitalik Buterin isn’t just the founder of Ethereum—he’s also a blogger. In this blog post from late last year, Buterin discusses some of his favorite applications built on Ethereum: prediction markets like Polymarket, where users can bet crypto on the outcome of events like elections. Buterin argues that prediction markets also act as news sites for non-bettors, opening the floodgates for many different kinds of info-based apps on Ethereum. Read the post here.

Silk Road, the dark web's first widely used market, proved the real-world utility of bitcoin

Named after the ancient intercontinental trade network between China and the Roman Empire, the anonymous market was active from early 2011 to October 2013. Before it was shut down, approximately 10,000 products—70% of which were illegal and controlled prescription drugs—were bought and sold using the cryptocurrency.

NFTs create a unique digital signature to prove ownership

NFTs create digital certificates for unique online collectibles, mainly on the Ethereum blockchain. Artists can leverage NFTs to verify their online works.

The different types of stablecoins include algorithmic stablecoins

In addition to fiat-backed stablecoins, commodity-backed stablecoins, and cryptocurrency-backed stablecoins, algorithmic stablecoins use smart contract-based mechanisms to maintain a stable value by responding to supply and demand.

Prediction market Kalshi's CEO Tarek Mansour ​​has said that prediction markets are similar to the stock market—except instead of buying and selling shares of companies, users buy and sell "yes" or "no" on whether an event is going to happen or not.

The benefits and risks of smart grids, from improved efficiency to cybersecurity risks

By using a network of devices, including digital meters, sensors, and controllers, smart grids can quickly detect mechanical issues and fluctuations in supply and demand, automatically adjusting electricity flow to prevent cascading failures. While this is important for variable solar and wind power generation, many of these computer systems are designed to be controlled remotely, which increases the risk of malicious access.

Prediction markets—the platforms where users can trade bets that pay out depending on certain event outcomes—have faced questions about insider trading.

Futures contracts are agreements to buy or sell a standardized asset at a specific future time

When it comes to commodity trading, these legally binding agreements tend to operate on a monthly basis. Futures contracts are typically traded on futures exchanges, like those operated by CME Group and the Intercontinental Exchange.

Crypto ETFs are driving cryptocurrency adoption

In 2024, the SEC approved ETFs that track the price of bitcoin called spot bitcoin ETFs. These funds have since significantly increased investment inflows into cryptocurrency markets.

Are smart cities a dumb idea?

Smart cities require vast troves of data to run, making their systems attractive to hackers. Listen to this one hour podcast to learn about the risks and what is being done to mitigate them.

The interoperable metaverse and what that means

This explainer video explores the challenges of achieving the interoperability needed to unify economies, avatars and systems across virtual worlds in the metaverse.

NFT trading volumes rose 700% in the third quarter of 2021

Non-fungible tokens, digital assets backed by smart contracts, gained mainstream recognition in 2021 as the digital assets’ popularity rose in tandem with investors’ appetite for risk. NFTs are unique and not divisible.

Cryptocurrencies are forms of digital currency

Cryptocurrency's key feature is decentralization. Unlike traditional money, they generally aren't controlled by a single authority. As of early 2025, cryptocurrencies had a cumulative market cap of almost $3.4T, making them worth more than some of the world's most valuable companies, like Google and Amazon (both valued at roughly $2.3T).