Remote backup describes a specific form of data back where the backed up data is stored remotely. It means in plain terms that the data is not stored on the computer system the backup was made but on another storage device.
These devices can be other computers connected in the same network, ftp servers or backup solutions in the cloud among others.
The benefit of storing the data remotely is that it remains accessible even if the source becomes inaccessible. This is for instance the case if a computer gets stolen or destroyed so that the data and local backups become inaccessible.
Most backup software programs provide options to store the backups locally and remotely. Remote backup solutions can cause privacy concerns depending on the security used to transfer and store the data on the remote servers.