Privacy coins are a type of cryptocurrency specifically designed to protect users' identities and their transaction details.
This is different from Bitcoin, which is pseudonymous (transactions are publicly visible on the blockchain, but real names are not listed); privacy coins use advanced cryptographic techniques to make transactions completely anonymous and untraceable, hiding two main pieces of information: who is sending/receiving and how much and the balance/transactions.
Advantages of Zcash (ZEC): Provides users with the option of transparent transactions (like Bitcoin) or protected (shielded) transactions using zk-SNARKs technology.