Definition
A descriptor wallet is defined by one or more output script descriptors rather than by a bare set of keys. An output descriptor, standardized in BIP380 and its companions, is a compact string that fully describes which output scripts (and therefore addresses) a wallet should produce. It encodes the script type such as P2WPKH or P2TR, the public or extended keys involved, the derivation path, and the master-key fingerprint, all wrapped with a checksum to catch transcription errors.
The problem descriptors solve
A seed phrase alone backs up the keys but not how to use them. After SegWit and Taproot added new output types, a restored wallet given only private keys cannot know which address formats to generate, leading to wallets that appear empty because they derived the wrong addresses. Descriptors remove that ambiguity by stating exactly what to derive, which is why a descriptor plus a seed is considered a complete, portable wallet backup.
Where descriptors shine
Descriptors were designed in part to fix incompatibilities between wallets when restoring a backup or exporting data for a watch-only setup. They make multisig portable too, since a single descriptor can capture an entire m-of-n policy, every cosigner key, path, and origin, in one verifiable string. Exporting that descriptor to other software reproduces the same wallet without trial and error.
Descriptors underpin reliable Watch-Only Wallets and portable Multisig configurations.
In Simple Terms
A descriptor wallet is defined by one or more output script descriptors rather than by a bare set of keys. An output descriptor, standardized in…