1. Introduction

1.1. Copyright Information

Copyright (c) 2002 by Jennifer Vesperman. This material may be distributed only subject to the terms and conditions set forth in the Open Publication License, v0.4 or later (the latest version is presently available at http://www.opencontent.org/openpub/).

1.2. Overview

All the information you keep in your computer is stored on a hard drive. The important thing to know about hard drives is that they have moving parts - and like all things which move, those parts wear out eventually. So you need to keep a copy of your information on something else as well.

That's not the only reason to keep a copy somewhere else - your computer may be in a fire or a flood. A thief might steal the computer. Lightning might strike it. Someone might make a mistake and wipe out your database, without doing any damage to the computer itself.

So we store the data somewhere else as well. Not instead - most things you can back your information onto aren't any safer than the hard drive. But having it in two places is safer than one. Having it in three is even safer.

And then we store the backup (the second place) somewhere safe. Preferably in a different building - if it's in the same building and the building burns down or floods, you've lost both your original information and your copy.