Encyclopedia

This Archive aims to provide the glossary terms and docs you need to understand Bitcoin and start building Bitcoin-based applications.

U

UASF

A Soft Fork activated by flag day or node enforcement instead of miner signalling.Not to...

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Unconfirmed transaction

A score indicating the number of blocks on the best block chain that would need...

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Unique Address

Address which are only used once to protect privacy and increase security.

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Unsolicited block push

When a miner sends a block message without sending an inv message first.

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URI qr code

A QR code containing a bitcoin: URI.

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User-activated soft fork

A Soft Fork activated by flag day or node enforcement instead of miner signalling.Not to...

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UTXO

An Unspent Transaction Output (UTXO) that can be spent as an input in a new...

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Documentation