The act of holding funds or assets in a third-party account to protect them during a transaction. If Bob wants to send money to Alice in exchange for a file, but they cannot conduct the exchange in person, then how can they trust each other to send the money and file to each other at the same time? Instead, Bob sends the money to Eve, a trusted party who holds the funds until Bob confirms that he has received the file from Alice. Eve then sends Alice the money. In Ethereum: If two low-reputation entities are engaged in commerce, the payer may wish to leave the funds with a high-reputation third party and instruct that party to send the funds to the payee only when the product is delivered. This reduces the risk of the payer or payee committing fraud.