Resolving mutual distrust structurally, not by asking either side to simply trust the other
Escrow places something consequential — funds, a cryptographic key, a credential — in the custody of a neutral third party pending a defined condition, rather than leaving it in the sole control of either the original holder or the intended eventual recipient. Neither party can unilaterally access or withhold what's held; release depends on the condition actually being satisfied, verified by the neutral holder rather than asserted by either interested party.
This is useful specifically where neither original party can be fully trusted to hold something alone until the right moment — a buyer shouldn't release funds before receiving what they paid for, and a seller shouldn't have to hand over goods before being paid, so a neutral party holding the funds in between resolves that mutual distrust structurally, without requiring either side to simply trust the other outright.
The arrangement's value lives entirely in how precisely the condition is written
The release condition is the specific, predefined event that triggers release, and it has to be defined precisely enough that the neutral holder can evaluate it objectively, without needing to exercise judgment about a dispute between the two original parties — which would defeat the entire point of using a neutral holder in the first place. A vaguely specified condition pushes exactly the judgment call escrow was meant to avoid back onto the escrow holder, or onto the two disputing parties who are, by definition, the ones who don't currently agree — the condition's value is entirely a function of how precisely and unambiguously it was actually written before the arrangement began.