When Bitcoin was released in 2009, it was the first-ever decentralized cryptocurrency. All Bitcoin transactions are verified and recorded on a public blockchain, which means that anyone in the world can see user balances and transaction data. This lack of privacy inspired a group of scientists to build something better, and in 2016, cryptography experts took Bitcoin’s open-source code and added zero-knowledge proofs (among other improvements) to create Zcash. Zcash offers all the conveniences of Bitcoin, but with full encryption to protect users’ financial information.
There are other important differences, e.g., a self-funding mechanism in Zcash, shorter confirmation times, a memo field, and more.