It’s necessary to make automatic backups of your site. Many hosting providers will do this for you automatically and keep a few recent version on their servers. However, it’s important to keep at least one backup somewhere other than the server that hosts the site. The hosting company might suddenly shut down or decide they don’t like you and lock your account. If they have the only copies of your data, you’re screwed.
That’s why I like to install UpdraftPlus WordPress Backup Plugin by updraftplus.com on every website I create. There are other backup plugins that are probably just as good, but I happen to like this one, and it lets you put your backups on Google Drive at no cost, which suits me because I keep a lot of stuff there anyway. You can also arrange to have the backups mailed to you, or pay a little extra for the ability to put them on Dropbox or other services.
If your site is fairly active, it’s best to set the backup schedule to weekly, so you don’t lose a lot of work if the server goes bye-bye. Also, set it to keep a few backups so if your site gets hacked and you want to go back to a good version, you have a few to choose from in case you don’t notice the hack right away.