ETH gas是什么以及Ethereum中的费用如何运作？

Why gas exists

Gas isn't just a toll — it's what keeps a shared, permissionless computer usable. It serves three purposes:

• Preventing spam. Because every operation costs something, malicious actors can't flood the network with frivolous or computationally expensive transactions.
• Paying validators. Fees compensate the validators who process transactions and secure the network.
• Allocating resources. The network's computing capacity is finite, so pricing it by demand ensures heavier operations pay proportionally more.

When you send a transaction you also set a gas limit — the maximum gas you're willing to spend. If execution runs past the limit the transaction fails, and the gas already consumed is not refunded, so wallets typically set sensible limits for you.

Gas beyond Ethereum

The same model applies across Ethereum Virtual Machine (EVM) blockchains, each with its own fee token — on Polygon, for example, gas is paid in POL. Other chains like Solana don't use the term "gas," but transactions still require the native token (SOL) to cover fees.

Keeping gas costs down

• Time your transactions. The base fee rises with congestion, so non-urgent transactions cost less during quiet periods.
• Use the fee presets. Choosing an economy setting when speed doesn't matter (see "Customizing fees" above) can meaningfully reduce what you pay.
• Consider Layer 2 networks. Rollups process transactions off the main chain and settle back to it, cutting fees substantially for everyday activity.