This article is general education about technology, not financial, tax or legal advice, and it does not recommend buying any asset. Crypto assets are volatile and you can lose everything you put in. Rules differ by country.
If Bitcoin is digital money, Ethereum is closer to a global, shared computer that anyone can run programs on. That idea sounds abstract, so here is a plain-English guide built on the Ethereum Foundation's own documentation (what Ethereum is, smart contracts, and gas fees). The documentation is written by the project's community, so it describes the benefits well, and we add the risks it mentions plus a few more.
Key takeaways
- Ethereum is a public blockchain and a platform for programs called smart contracts.
- You pay fees (gas) in its native currency, ether (ETH), to use it.
- Since 2022 it uses proof of stake, which cut energy use by about 99% according to the project.
- Smart contracts are only as good as their code, and approving transactions you do not understand is dangerous.
What Is Ethereum?
Per ethereum.org, Ethereum is a public blockchain launched in 2015 that also serves as a platform for building software. Thousands of independent nodes record every transaction, so no single company or government controls it. Its native cryptocurrency is ether (ETH).
Smart Contracts
Smart contracts are programs stored on Ethereum that run "if this, then that" logic. The documentation compares them to a vending machine: the item is released only after every required input is provided. Key properties:
- Once deployed, the code cannot easily be altered, so outcomes follow the rules written in the code.
- They execute automatically when preset conditions are met, with no intermediary to interpret or enforce the result.
- Code and transactions are public, so anyone can audit transfers and review terms before interacting.
- Given the same inputs, they produce the same result every time.
Applications built on smart contracts are called dapps. Categories include decentralised finance (DeFi), stablecoins, NFTs, games and social media. Users typically connect through a browser and a crypto wallet instead of creating a traditional account.
Gas: Why Every Action Costs Something
Gas measures how much computational work an operation needs. The fee equals the gas used multiplied by the price per unit, paid in ETH and usually quoted in gwei (one-billionth of an ETH). Fees exist to pay for the computation validators perform and to make flooding the network with junk transactions costly. The documentation adds details that matter in practice:
- A fee has a base fee, set by the protocol and burned (removed from circulation), and a priority fee (tip) for validators.
- The base fee adjusts with demand, rising or falling by up to 12.5% per block depending on how full blocks are.
- Unused gas is refunded, but failed transactions still cost gas.
- High fees usually mean many people are competing for block space, and complex contracts use more gas.
Proof of Stake and Staking
Since 2022 Ethereum has used proof of stake instead of mining. Validators lock up ETH as a security deposit to process transactions and earn rewards, and dishonest behaviour can cost them part of their stake. ethereum.org says this cut the network's energy use by about 99%. Staking involves its own risks, including lock-up periods, technical failure and the risk of the provider you use failing.
Layer 2 Networks
Layer 2 networks sit on top of Ethereum and handle transactions more cheaply and quickly while still relying on Ethereum's security. They are a major effort to reduce fees, though they add their own technical and bridging risks.
Limitations and Risks
- Blind signing. The documentation notes raw transaction data is built for software and is hard for humans to read, so users may approve transactions without knowing what they do. Standards called "clear signing" aim to translate contract data into readable descriptions. Be extremely careful with approvals.
- Code is law, bugs included. Because code is fixed and execution is automatic, the outcome depends entirely on how the code was written. A flaw can mean lost funds.
- Public records. Activity is visible to observers, even though identities are not directly shown.
- Volatility and scams. ETH prices are volatile, and fake tokens and malicious contracts are common; see crypto scams.
Why It Matters for Businesses
Smart contracts are used for stablecoins, automated agreements and payments, and some companies explore them for supply chains or loyalty programmes. For most small businesses the practical question is more modest: whether to accept crypto payments; see how to accept crypto payments on your website. Compare with Bitcoin and learn about stable-value tokens in stablecoins explained.
For Developers
Building on Ethereum means writing, testing and auditing contracts with great care, because deployed code is hard to change. If you are exploring blockchain features for a product, Node-devs can help you decide whether it is the right tool; for many apps a conventional database is simpler, cheaper and safer.
References and further reading
This guide was compiled from the sources below. We compared them, kept the points they agree on and wrote the article in our own words. Check the originals for more detail.
- What is Ethereum? (ethereum.org)
- Smart contracts (ethereum.org)
- Gas and fees (ethereum.org)
