Privacy coin is defined as a cryptocurrency that hides data about its users. At a minimum, privacy coins hide identities. They also often hide the amount of cryptocurency traded and held in wallets.
Bitcoin is not a true privacy coin. Bitcoin users are identified by their public address and computer programs exist which can, in time, link those addresses to actual identities. Bitcoin transactions and wallets are also publicly visible data.
Nevertheless, there are many privacy coins. Zcash, Dash, and Monero are the 3 most popular options, but there are dozens more.