FileVault is an encryption program built into the macOS operating system, used to secure data stored on a Mac computer. It encrypts the entire drive using the user's login password as the encryption key, making it virtually impossible for anyone to gain access to the data without the correct password. FileVault also provides secure deletion of files, making it harder for deleted data to be recovered. FileVault also helps protect against malicious software, as it is difficult for malicious software to gain access to encrypted files. Finally, FileVault can also be used to encrypt external drives, providing an additional layer of security for data stored on those drives.
Discontinued Currently not maintained. The latest version, TrueCrypt 7.1a, is still available for download and development has continued through forks https://alternativeapp.info/software/veracrypt/ and https://alternativeapp.info/software/ciphershed/. "TrueCrypt development was terminated in 5/2014 after Microsoft ended support for Windows XP. Windows 8/7 / Vista and later offer integrated support for encrypted disks and virtual disk images."