When you run an Internet site, having a backup is something rather necessary, particularly if you have important information or you have invested cash and time in creating the site. There are numerous situations why you could need a backup - if you update a script and something fails, if you delete a file or a whole folder unintentionally, and so on. Having regular backups will help you avoid any loss of information or at least minimize the damage, which is still better than losing the entire site. You'll be able to download a copy of your content on your computer every now and then, but because you can't do that after every single change, you'll have to rely on the backups which your hosting provider generates. Since that's something extremely necessary, you have to make sure that they keep up-to-date backups, since a backup executed once every one or two weeks might not do any good if you run a site such as an online store or an accommodation reservation site.