Ycash is a digital currency, like Bitcoin or Zcash.
In fact, the software for Ycash is based on the software for Zcash, which in turn is based on the software for Bitcoin.
Ycash also shares something else in common with Zcash: shared blockchain history. The first 570,000 blocks of the Ycash blockchain are the same as the first 570,000 blocks of the Zcash blockchain.
Like Bitcoin and Zcash, the total supply of Ycash is forever capped at 21 million coins. So, unlike government-issued paper cash, you never have to worry about inflation devaluing your Ycash.
Bitcoin is truly revolutionary, but it suffers from several problems, including the following two key problems:
The Privacy Problem. Bitcoin lacks privacy. The whole world can see all of your transactions.
The Distribution Problem. The ongoing initial distribution of bitcoin (via "mining") is dominated by manufacturers of specialized computer hardware and their business partners.
Zcash improved upon Bitcoin by implementing a revolutionary solution to The Privacy Problem. But The Distribution Problem remains.
By building upon the Zcash codebase, Ycash leverages Zcash's solution to The Privacy Problem. And by aggressively pursuing mining on commodity hardware by all available means, including periodic changes to Ycash's mining algorithm, Ycash aims to address The Distribution Problem.
We believe that addressing The Distribution Problem is necessary for a digital currency to achieve widespread, grassroots adoption. As one engineer working on Ycash put it, if the mining process is largely controlled by specialized hardware created by a far-off foreign manufacturer, the coin seems "distant". Mining is an important way for users to participate in a digital currency's community, and mining on commodity hardware opens up the mining process up to a much larger group of users.
Another key component of Ycash's approach to addressing The Distribution Problem is upholding a promise that originated from Zcash: that 90% of the coins would be distributed via the mining process. The structure of the Ycash Development Fund upholds that promise: With 5% of the coins starting at block height 570,000 going to the Ycash Development Fund, 90% of the total 21 million Ycash coins will be allocated via the free market mining process.