Ethereum (ETH) Exchange

Ethereum is a programmable chain: besides moving its own coin, ether, it runs smart contracts — code that executes exactly as written and cannot be quietly changed afterwards. Most of what people call DeFi, NFTs and on-chain gaming lives here, which makes ether the settlement asset of that whole layer rather than just another currency.

Every action on the network costs gas, paid in ether. The price of gas moves with demand, so a transfer during a quiet hour can cost cents and the same transfer during a busy one several dollars. Since the switch to proof of stake in 2022 the chain is secured by validators who lock ether as collateral instead of by mining, and part of every fee is burned, which slowly reduces supply when the network is busy.

Ether exists in several places at once: on the main chain and on rollups like Arbitrum, Base and Optimism, which settle back to it. The token is the same, but the network matters when you send: an address is identical in form on all of them, and choosing the wrong one is the most common way people lose a transfer.

For swapping, ether is the middle ground between Bitcoin and stablecoins: liquid enough to trade in size, but with a use beyond storage — you need it to do anything on the contract layer at all.

Practical points for a swap. One Ethereum address works on the main chain and on every rollup, and that is exactly where people lose money: the address looks correct on all of them, but funds sent to Arbitrum do not appear on the main chain. Confirm which network the receiving wallet is watching, not just the address.

Gas is paid in ether even when you are moving something else, so leaving a small ether balance in the wallet is what keeps the rest of it usable. A wallet holding only tokens and no ether cannot send them at all until you top it up, and topping up needs an incoming transfer — which is the situation people usually discover at the worst moment.