Rsync is a mighty tool to perform synchronization on Linux systems. In case you want to back up a folder from another machine to your local environment, just use the following snippet:

rsync -P -r remoteuser@remotehost:/path/to/remote/folder /path/to/local/folder

Parameter -P is required to show the progress. Parameter -r defines that you want to sync between two different machines. Followed up by user @ host of the remote machine and the local path.

Use case: remote folder /var/www/website/subdomain to local /var/www/new_website/subdomain:

rsync -P -r remoteuser@remotehost:/var/www/website/subdomain /var/www/new_website