SegWit
A Bitcoin upgrade that changes how transaction signature data is stored, making transactions smaller to process and fixing transaction malleability.
SegWit, short for Segregated Witness, is a Bitcoin protocol upgrade that separates a transaction’s signature data, called witness data, from the main transaction data. Signatures are still checked by the network, but they are stored and counted in a more efficient way. This lets more transaction data fit into each block without simply raising Bitcoin’s traditional block size limit, helping reduce congestion and fees when network demand is high.
SegWit also fixed a problem called transaction malleability, where certain transaction details could be altered before confirmation without changing the actual transfer. That fix made it easier to build second-layer systems such as the Lightning Network, which rely on stable transaction identifiers. In practice, a SegWit Bitcoin address often starts with “bc1” or sometimes “3”; sending from a SegWit-compatible wallet is like using more efficient packaging for the same payment, so the network can process it with less block space.
Other terms in Bitcoin
ASIC
A specialized computer chip built to do one task very efficiently, commonly used in Bitcoin mining to perform hashing calculations.
BTC
The ticker symbol for bitcoin, the native currency of the Bitcoin network.
Bitcoin
A decentralized digital currency and payment network that lets people send value without relying on a bank or central authority.
Block Height
A block height is the number that shows a block’s position in a blockchain, counted from the first block.