In short - confidential payments. A bit longer... Normally when you send a payment with crypto currencies you leave a trace in the blockchain. i.e. other peop

In short - confidential payments. A bit longer... Normally when you send a payment with crypto currencies you leave a trace in the blockchain. i.e. other people can see which address is sending how much to where. This information is required so that the transaction can be validated by all nodes. The zk-SNARK technology allows you to send a payment without revealing the who sent how much to where.