Tar (tape archive) is a command-line utility used for creating backups, and it's often used in combination with compression utilities like gzip or bzip2.
Rsync is a powerful tool for efficiently transferring and synchronizing files between directories, or even between different servers.
dd is a versatile command-line utility primarily used for low-level copying and conversion of data. This command creates an image backup of the entire disk (/dev/sda) and saves it to a specified file.
dump is a command-line backup tool specifically designed for creating backups of file systems. This command creates a level 0 dump of the specified file system (/dev/sda1) and saves it to the specified file.
Secure Copy (scp) is a command-line utility for securely copying files between hosts on a network. This command copies the specified file or directory to a remote host using SSH.