In simple terms
To swap means exchanging one token for another. On a DEX, the wallet sends a transaction to one or more smart contracts. The interface may search routes across several pools, but the result matters only when the transaction executes.
Quote and execution
The quote displays an estimated amount, route, and conditions at one moment. Prices and liquidity may change before confirmation. The transaction sets a minimum received amount, slippage tolerance, or deadline; if the conditions no longer hold, it may fail while still consuming gas.
What to check
Verify the network and token address, amount sent, minimum received, price impact, fees, route, and network cost. An ERC-20 may require an approval first: distinguish the spending permission from the swap and limit it when possible. A ticker alone does not identify an asset.
What it does not prove
A confirmed swap does not prove that the price was best, the token safe, or the operation profitable. Price impact and slippage are different: the former is the effect of the trade on pool liquidity; the latter is the gap between the expected result and the execution accepted.
Sources
- Uniswap Labs, How to swap tokens with the Uniswap web app — Covers contract selection, review, approval, signing, gas, and on-chain confirmation.
- Uniswap Labs, What is price impact? — Separates the effect of trade size on pool liquidity.
- Ethereum.org, Interacting with smart contracts — Frames a swap as a signed state-changing write included in a block.