What is Zcash?
Zcash is a cryptocurrency aimed at using cryptography to provide enhanced privacy for its users compared to other cryptocurrencies such as Bitcoin. Zcash is based on Bitcoin's codebase. It shares many similarities such as a fixed total supply of 21 million units.
Transactions can be "transparent" and similar to bitcoin transactions in which case they are controlled by a t-addr, or can be a type of zero-knowledge proof called zk-SNARKs; the transactions are then said to be "shielded" and are controlled by a z-addr. Zcash coins are either in a transparent pool or a shielded pool; as of December 2017 only around 4% of Zcash coins were in the shielded pool and at that time most cryptocurrency wallet programs did not support z-addrs and no web-based wallets supported them. The shielded pool of Zcash coins were further analyzed for security and it was found that the anonymity set can be shrunk considerably by heuristics-based identifiable patterns of usage.
Zcash affords private transactors the option of "selective disclosure", allowing a user to prove payment for auditing purposes. One such reason is to allow private transactors the choice to comply with anti-money laundering or tax regulations. "Transactions are auditable but disclosure is under the participant's control." The company has hosted virtual meetings with law enforcement agencies around the U.S. to explain these fundamentals and has gone on the record of saying that "they did not develop the currency to facilitate illegal activity".
What is Zcash faucet?
zCash faucets are a reward system, in the form of a website or app, that dispenses rewards in the form of a satoshi, which is a hundredth of a millionth ZEC, for visitors to claim in exchange for completing a captcha or task as described by the website. There are also faucets that dispense alternative cryptocurrencies. Rewards are dispensed at various predetermined intervals of time. Faucets usually give fractions of a zCash, but the amount will typically fluctuate according to the value of zCash.
Faucets are a great way to help introduce new people to zCash, or to your favourite altcoin. Many faucets provide information to newbies as well as offering them some free coins so that they can try before they buy, experimenting with a test transaction or two before putting real money on the line. Since this whole area is so new and a bit scary to some people, who perhaps don't quite trust it with their hard earned cash yet, this is a great way to promote digital currency and bring in new users.