The WordPress codex describes the backup process at a high level. If you’re using a managed host, you should check whether or not they provide backup services for you. They should. However, it’s still best practice to have an alternative site backup.
If you’re self-hosting WordPress, you’ll need to regularly backup the WordPress MySQL database as well as the file system with the themes, plugins and media files. You may also want to backup your Apache site configuration files. If you’re running your site in the AWS cloud, you can manually build a snapshot of your entire volume. You can also customize a script to schedule snapshots using the AWS API or use a service such as Skeddly.