Why do you think that printers, photocopying machines, scanners, diskettes, CDs and DVDs were developed in this day and age? All of these have only one thing in common – backup. Producing a backup copy is vital, either soft or hard, that you still can access or read the information you need if in case the original copy is stolen, lost or got damaged. This concept is the same when dealing large volumes of information that are kept on database servers.
There is no such perfect system in this world that even high powered machines are still susceptible to change and may lead to malfunction over time. Plus, also take note of unexpected disasters that may happen. Examples would be fire, floods and earthquakes to name a few. Human errors may also occur, though this may seem most unlikely to happen since proper training can always be given to the users of the system. Another human-imposed activity would be hacking and other nuisance that can cause too much trouble. When worse comes to worst that when such unfortunate events arise and everything is lost and may seem to be unrecoverable, there is only one thing that you can cling on. This would be your database backup server.
But then again, a good thing to point though is that the database backup server should be kept on another site or location. This could be outside building premises or perimeters or it could also be inside the business facility but is kept on a more secure room or building. This is to ensure the safety of valuable information that would lead to business continuity as well.