The Taproot soft fork activates at block 709,632, Bitcoin's most significant protocol upgrade since SegWit in 2017. Taproot introduced Schnorr signatures, improving privacy, efficiency, and smart contract capabilities.
The upgrade made multisig transactions indistinguishable from single-sig transactions on-chain, enhanced Lightning Network channel opens, and laid the groundwork for more complex Bitcoin scripts. Notably, Taproot achieved activation through the Speedy Trial method after contentious debates about activation mechanisms.
Bitcoin Wiki: Taproot