What is SegWit (Segregated Witness)?
Segregated Witness is a Bitcoin soft fork activated in August 2017 that moved signature ('witness') data outside the original transaction structure. SegWit fixed transaction malleability, effectively increased block capacity and was a prerequisite for the Lightning Network and Taproot.
Why SegWit (Segregated Witness) matters
Understanding SegWit (Segregated Witness) is part of building a solid mental model of how Bitcoin, blockchain and Web3 systems actually work. Concepts in the Bitcoin category sit at the foundation of the broader stack — get them right and the rest is far easier.
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Related terms
- Soft Fork — A backwards-compatible protocol upgrade.
- Taproot — Bitcoin's 2021 upgrade improving privacy and scripting.
- Lightning Network — Bitcoin's payment-channel scaling layer.
More bitcoin terms
- Address (Bitcoin / Crypto Address) — A public destination for receiving cryptocurrency.
- Block Header — The metadata at the top of each block.
- Block Reward — New coins paid to the miner of a block.
- Difficulty — A parameter that controls how hard it is to mine a block.
- Double Spend — Attempting to spend the same coin twice.
- Halving — The scheduled 50% cut in Bitcoin's block subsidy.
- Hash Rate — The total computational power securing the network.
- Mining — Producing new blocks by performing Proof of Work.
Keep exploring
Continue with the full blockchain glossary — 136 terms in total — or read the developer blog and FAQ for deeper context.