ZCash is a privacy driven cryptocurrency. Although it shares some similarities with other currencies, such as Bitcoin, it does have many different features. It uses the Equihash as an algorithm – an asymmetric memory-hard Proof of Work algorithm, which is based on the generalised birthday problem. It works, only if there are high RAM requirements, which can then bottleneck the generation of proofs and making ASIC development unfeasible.
ZCash has very unique features, and uses zero-knowledge Succinct Non-Interactive Arguments of Knowledge (zk-SNARKs), which will ensure that all of the information is encrypted, all without the possibility of double-sending. The only information that can be seen regarding all of the transactions is the time in which they take place.