Zcash's core differentiator, shielded transactions, are computationally heavy – so much so that most users and exchanges can't support it.
Heralded as a privacy breakthrough in the crypto community, shielded transactions run a type of cryptography named zk-snarks in order to obscure transaction data. But a new upgrade, predicted to activate on October 29, is being touted as a significant improvement of the usability of the protocol overall, but specifically for the use of these privacy-enabling transactions.
Dubbed Sapling, the hard fork upgrade has been the primary focus of the Zcash Company, the for-profit responsible for developing on the cryptocurrency, since its launch in 2016.