Definition
Taproot (BIP 340, 341, 342) was activated in November 2021. It introduced Schnorr signatures (replacing ECDSA for Taproot outputs), which are more efficient and enable key aggregation. This makes complex multi-signature transactions look identical to simple single-signature ones on the blockchain, improving privacy.
Taproot also introduced Tapscript, an upgraded scripting language that enables more complex smart contracts on Bitcoin. The upgrade was notable for achieving broad consensus among miners during its signaling period.
In Simple Terms
A 2021 upgrade adding Schnorr signatures for better privacy and efficiency in complex Bitcoin transactions.
A 2021 soft fork that introduced Schnorr signatures and improved Bitcoin's scripting capabilities, enhancing privacy and efficiency for complex transactions.