Zcash is a digital currency in the vein of bitcoin, except it makes anonymous all the details of a transaction; i.e. the transacting parties and the value being transacted.
Using this shield feature, blockchain “watchers” cannot track down the sender, the receiver or the value.
Zcash is fungible in that it sets apart shielded coins from the transaction history, making the units equally interchangeable with other currencies.
Zcash utilizes advanced cryptography, and using the zero-knowledge proof, fully encrypted transactions are confirmed.
Bitcoin transactions are not anonymous; they are merely pseudonymous. However, Zcash is truly anonymous because of fully encrypted transactions.
All of these stellar features have contributed toward the gains in price of Zcash. It remains to be seen whether Zcash will overtake bitcoin in value.