Percona XtraBackup User Manual

Percona XtraBackup is a set of following tools:

innobackupex is the symlink for xtrabackup. innobackupex still supports all features and syntax as 2.2 version did, but is now deprecated and will be removed in next major release.
a compiled C binary that provides functionality to backup a whole MySQL database instance with MyISAM, InnoDB, and XtraDB tables.
utility used for encrypting and decrypting backup files.
utility that allows streaming and extracting files to/from the xbstream format.
utility used for downloading and uploading full or part of xbstream archive from/to cloud.

After Percona XtraBackup 2.3 release the recommend way to take the backup is using the xtrabackup script. More information on script options can be found in how to use xtrabackup.