A backup is a copy of an Internet site that is kept on a separate server and can be restored if a problem occurs with the live website - an unsuccessful script update, an unintended deletion of a file or of your entire database, etcetera. Restoring the website the way it was shall take away or lessen the damage the issue may have caused, which is by all means a much better option than having to rebuild the entire website from scratch. Though you could download a copy of your content on your personal computer, keeping a backup is a functionality that almost all hosting companies include as part of their plans. You'll have to take a look at how often they do that, though, because some companies generate a backup only once every week, which may be far from enough for a booking Internet site or an e-commerce portal in which the data is updated every day. Make sure that you see how quick and simple a backup could be restored, which can be essential if some issue appears on your Internet site.