Bitrix Environment, and consequently a web project on which it is built, stores information:
To create a copy of the web project, use the form "Settings > Tools > Backup".
However, it is strongly recommended that you set up your system to create automated regular backups to protect your project against software or hardware failure. Use web cluster technology to reach even higher level of robustness and availability of your data.
For example, if you create backups manually, the page "Settings > Tools > Backup" must contain backup copies for a certain period of time (for example, a week), and the most recent backup copy must be created one day ago.
If your system is configured for automated backups, using either the system tools or by hosting company, you must ensure that such backups really take place. Ask your hosting company to show you the backups. You should control the backup on a regular basis.
The problem is that, while the backup copiess are really created, they do not contain all data required for successful recovery, or data may be damaged. To prevent such situations, attempt to recover the web project from the backup copy to a temporary location on a regular basis.
If your project is sensitive to loss of files, configure the system for more frequent backups or, if the total file size is too large, use the file system snapshot technology (LVM, special storages, cloud storages etc.)