Bitcoin Terms Beginning with W

A wallet is a piece of software which generates and stores public and private keys, allowing users to send, receive, and store bitcoin.

Wallet Import Format (WIF) is a standardized method for displaying Bitcoin private keys. WIF format was standardized in order to allow all Bitcoin wallets to import and export private keys.

Watch-only is a term used to describe wallets which store public keys but do not store or use private keys.

A Watchtower is a service that surveils a particular Lightning channel to guard against fraud. Watchtowers allow Lightning users to have a semi-trusted third party watch over their channel to prevent double spends.

Weekly moving average is a stock indicator used to understand price movement of a stock, while mitigating the impact of short-term fluctuations.

A weight unit is the unit used to measure the size of transactions and blocks as of the SegWit upgrade. Weight units are abbreviated as ‘wu’.

Within the context of Bitcoin, a whale is someone who holds a large amount of bitcoin. There is no widely accepted threshold for qualifying as a whale.

A whitepaper introduces a new idea or topic for discussion. The Bitcoin whitepaper introduced Bitcoin as a “peer-to-peer electronic cash system” on October 31, 2008.

The witness of a transaction is a section of SegWit transactions not included when a transaction is hashed and signed. The witness contains the witnessScripts for all SegWit inputs of a transaction.

The Witness Script is the script which outlines the requirements to spend a Pay-to-Witness-Pubkey-Hash (P2WSH) output, much like the Redeem Script does for a P2SH output. Most commonly, Witness Scripts define the setup of a SegWit multisig wallet.

Wrapped SegWit is a design implementation meant to enable wallets and other Bitcoin software to more easily support SegWit. Wrapped SegWit outputs look like P2SH outputs, but can be spent similarly to SegWit outputs.

The witness transaction ID (wtxid) of a transaction is calculated by taking the double SHA-256 hash of a serialized transaction, including its SegWit marker, version, and witness.