Gas

The close-up. Every action on a programmable blockchain — sending tokens, swapping assets, minting an NFT — asks the network to do work. Gas is the unit that measures that work. More complex operations consume more gas, and the sender pays a fee to have it executed. That fee is what compensates the validators or miners who add the transaction to a block and keep the ledger honest. Gas also acts as a safeguard: because computation costs something, the network is protected from spam and from programs that would otherwise loop forever.

The wide shot. Gas reflects a basic truth about shared, decentralized systems — that blockspace is finite and demand for it competes. When many people transact at once, senders bid higher fees to be included sooner, so the cost of gas rises and falls with network activity. This pricing is what lets an open network allocate its limited capacity without a central operator deciding who goes first.

Practically, a gas fee is usually paid in the network's native asset, such as a chain's base token. Wallets estimate the amount for you, and tools exist to check current conditions before you send. Understanding gas helps explain why the same transaction can feel cheap at one moment and expensive at another, and why scaling designs aim to make blockspace go further. Always do your own research before transacting.