After you configure backup settings using backup plugin, backup jobs will run automatically and start taking backups at the prescribed interval
Answers
When any plugin is added for backingup a sysytem at a fixed regular interval, then the whole systems data gets backed after the intervals prescribed in the plugin.
When something runs in background the usually it is known as a service.When we run a service in a system, it always works in background. Here the plugin can also be considered as a service.
A plugin is generally used as it easily helps to run and also execute a programme without the need of any code.
Thus, it is easy to understand that a backup plugin can help to run all the processes related to backup automatically by executing its programme regularly at an interval as coded.
Thus once you configure it i.e. backup settings using a backup plugin, the rest things get done at an interval which has been prescribed.