Taproot is an instantiation of a soft fork for Bitcoin, intended to both improve privacy and improve other aspects tied to more complex transactions.
Its goal is to change the way in which the scripts operate within Bitcoin in order to improve the blockchain’s privacy, scalability and security. Taproot is designed to achieve by furnishing Bitcoin with a signature scheme known as Schnorr signatures. Schnorr Signatures were developed by Claus Schnorr and offer an advantage insofar as they can take multiple keys within a complex Bitcoin transaction and produce a single signature.
Taproot even makes it possible to hide that a Bitcoin script has run altogether. Anyone monitoring the blockchain would see nothing but peer-to-peer transactions, even where more complex methods have in fact been used.