What Is Ethereum and How Is It Different From Bitcoin?

Ethereum is a blockchain built to run programs, while Bitcoin is a blockchain built to be money. That one design choice explains nearly every other difference between them. Bitcoin keeps its rules deliberately small and rigid so that its 21 million coin limit and its security assumptions are as close to unchangeable as software gets. Ethereum ships a general-purpose computer on top of its blockchain, so developers can deploy applications, called smart contracts, that hold and move value automatically. Ethereum also runs on a fundamentally different engine: since September 15, 2022, it has used proof of stake, in which coin holders rather than miners secure the network. Understanding both systems, and why neither is simply a better version of the other, is one of the most useful mental upgrades in crypto.

Two networks with different jobs

Bitcoin launched in 2009 with a narrow goal: electronic cash that no government or company issues or controls. Its scripting abilities are intentionally limited, because every feature added to a monetary network is also new attack surface. The result is an asset whose main selling points are scarcity, neutrality, and resistance to change. If you want the fuller story, start with what bitcoin is.

Ethereum launched in 2015, proposed by the programmer Vitalik Buterin, with the opposite ambition: a shared world computer. Anyone can deploy code to it, and that code runs exactly as written for anyone who interacts with it, with no company hosting it and no admin able to switch it off. Those programs, smart contracts, are the foundation for decentralized exchanges, lending markets, stablecoins, tokenized assets, and most of what gets labeled DeFi and web3.

A useful shorthand: bitcoin competes with gold and money. Ether, the currency of Ethereum, is closer to a commodity that fuels a computing platform, plus a bond-like yield for those who stake it.

Proof of stake: how Ethereum runs after the Merge

For its first seven years, Ethereum used proof of work like Bitcoin: miners burned electricity racing to add blocks. In an upgrade known as the Merge, completed on September 15, 2022, Ethereum switched to proof of stake. Validators lock up ETH as collateral for the right to propose and confirm blocks. Honest work earns rewards; provable cheating gets a validator's stake partially destroyed, a penalty called slashing. Security now comes from capital at risk inside the system rather than energy spent outside it.

The most measurable consequence: the network's energy use fell by roughly 99.95 percent, taking the strongest environmental criticism of crypto off the table for Ethereum specifically.

Bitcoin, by contrast, has kept proof of work on purpose. Its supporters argue that anchoring security to physical energy, and refusing to change the engine, is precisely what makes bitcoin credible as money. Bitcoin's monetary schedule marches on regardless: the April 2024 halving cut the reward for each mined block to 3.125 BTC, the fourth such cut on the way to the 21 million cap.

Ether, gas, and what you pay

Every action on Ethereum consumes gas, a unit measuring computational work. A simple ETH transfer costs 21,000 gas; swapping tokens or minting something costs more because more code runs. You pay for gas in ETH, and the price per unit floats with demand, so fees are cheap when the network is quiet and can spike sharply during frenzies.

Since a 2021 upgrade known as EIP-1559, the base portion of every fee is burned, permanently removing that ETH from circulation. This ties supply to usage: heavy network activity can burn ETH faster than staking rewards issue it. Unlike bitcoin, ether has no fixed supply cap; its issuance is low and offset by burning, but the schedule is a protocol design that has changed before and can change again. That flexibility is a real difference from bitcoin's hard-coded scarcity, and how much it matters is a genuine point of disagreement between the two communities.

Layer 2 rollups: where the activity went

Ethereum's base layer handles only a limited number of transactions per second, and its scaling strategy is not to force everything through that bottleneck. Instead, most user activity has moved to layer 2 rollups: separate networks such as Arbitrum, Base, and OP Mainnet that execute transactions cheaply in bulk, then post compressed data back to Ethereum, inheriting its security.

Three upgrades built this into a working system. The Dencun upgrade in March 2024 introduced blob space, a dedicated data lane for rollups that cut what users pay on them dramatically. The Pectra upgrade in May 2025 doubled blob capacity and improved wallet capabilities and staking mechanics. The Fusaka upgrade, activated on December 3, 2025, added PeerDAS, which lets nodes verify blob data by sampling instead of downloading everything, opening the way to several times more rollup throughput.

The practical takeaway for a newcomer: using Ethereum today usually means using a layer 2, where transactions cost a small fraction of what mainnet charges. The tradeoffs are honest ones: moving funds between layers takes an extra step, and most rollups still rely on centralized sequencers to order transactions, a known weak point their roadmaps promise to fix.

Staking: yield with strings attached

Proof of stake gives ETH holders something bitcoin deliberately lacks: native yield. Running your own validator requires 32 ETH and some technical commitment, so most people stake through pooled services, liquid staking tokens such as Lido's stETH, or custodial staking at exchanges like Kraken where available. Roughly 30 percent of all ETH is now staked, and rewards have compressed to around 3 percent a year as more capital joined.

The strings: staking rewards are paid for taking real risks. Validators can be slashed for misbehavior or penalized for downtime, liquid staking tokens can trade below the value of the ETH they represent during market stress, and custodial staking adds counterparty risk on top. Staking yield is compensation for securing a network, not interest from a savings account.

Bitcoin has no staking, because it has no proof of stake. Anything marketed as bitcoin yield is a lending or trading arrangement wearing bitcoin's name, with all the counterparty risk that implies. Several such lenders failed in 2022 and took customer coins down with them.

ETFs put both assets in brokerage accounts

Regulated US funds now hold both assets directly. The SEC approved 11 spot bitcoin exchange-traded funds on January 10, 2024, and they began trading the next day. Spot ether ETFs followed on July 23, 2024. For many investors this is the simplest exposure: a familiar brokerage wrapper, with custody handled by professionals.

The tradeoff mirrors the exchange-versus-self-custody choice everywhere in crypto. An ETF share is a claim on coins a custodian holds; you cannot withdraw the underlying asset, move it on-chain, or use it in applications, and you pay an ongoing management fee. Owning coins yourself, ideally in a hardware wallet, gives you the actual asset with the actual responsibilities. Neither route is wrong; they answer different needs.

An honest comparison

Where each side is strong, plainly stated. Bitcoin's strength is credibility through rigidity: a fixed supply, a simple design, and a seventeen-year record of resisting change. Its weakness is that rigidity limits what it can do, and its long-term security budget must eventually migrate from shrinking block rewards to transaction fees, an open question the halvings make steadily more real. Ethereum's strength is expressiveness: it hosts most of the useful applications in crypto, and its fee burning plus staking give the asset cash-flow-like properties. Its weaknesses are complexity, a larger attack surface, reliance on continued good governance of frequent upgrades, and lingering centralization concerns around large staking pools and rollup sequencers.

Both assets remain highly volatile, and drawdowns of half or more have happened repeatedly in both. ETFs and regulation changed who can buy them, not how much they can fall.

The bottom line

Treat bitcoin and Ethereum as two different bets, not two brands of the same thing. Bitcoin is a bet that an unchangeable, scarce digital money is valuable. Ethereum is a bet that a neutral, programmable settlement layer, and the asset that fuels and secures it, is valuable. You can hold both, either, or neither, but evaluate them on their own terms. If you are starting from zero, learn how bitcoin works first; it is the simpler system, and every idea in Ethereum is easier to grasp once you understand what it deliberately traded away.