Bitcoin users may, before long, be able to benefit from a trick called “Taproot.” First proposed by Bitcoin Core contributor and former Blockstream CTO Gregory Maxwell, Taproot would expand on Bitcoin’s smart contract flexibility, while offering more privacy in doing so. Even the most complex smart contracts would, on the blockchain, typically be indistinguishable from regular transactions.

While a big undertaking, this is not just theory. Several of the most prolific Bitcoin Core contributors — including Pieter Wuille, Anthony Towns, Johnson Lau, Jonas Nick, Andrew Poelstra, Tim Ruffing, Rusty Russell and, indeed, Gregory Maxwell — are working on a Schnorr signature proposal that would include Taproot, all in one protocol upgrade.

Here’s what Taproot is and how it works...
https://bitcoinmagazine.com/articles/taproot-coming-what-it-and-how-it-will-benefit-bitcoin/