Backups are primarily used for operational recovery, to quickly recover an overwritten file or corrupted database. The focus is on speed, both to back up and recover, and on data integrity. Archives, on the other hand, typically store a version of a file that no longer changing, or should not be changing.
For example, an accountant for a small business that uses QuickBooks will back up his files regularly in order to prevent a disastrous loss of inform. He will entrust that information to an online backup system that is updated at the end of each business day.
This way, if a problem occurs with the individual computer or network, then there is a way to resurrect the book without having to enter a month of work.
Archiving, on the other hand, is the equivalent of a long term insurance policy for files that are rarely accessed or never changed.
This type of storage creates a history of the files in an authentic form that can be accessed weeks from now or years from now. The storage media for archiving requires that it have a long, stable life.
If the owner of the company died tomorrow, where would you begin to look for important documents? Or what if an audit of 2003 came up? Creating an archive is essential to traching down vital information to a company or individual.
Typically, archives have been stored on magnetic tapes in the past, but with cost of online data archiving solutions becoming more practical and inexpensive, you will see more use of them.
Offsite data archiving is highly recommended in the even t of a disaster.
Another way of looking at the differences is that backup contains multiple restore points, allowing you to go back in time in case of a virus, accidental deletion or accidentally saving over a file.
Archived information will only store a singly version of a file and this is rarely changing, if ever at all. Often archived data will also span decades of files.
Archiving may require certain policies or rules that approve who have access, how long the records need to be stored etc.
