Berlin - Suddenly there's a splash. The smartphone you put down at the edge of the sink has slipped into the water and the fastest reactions are of no avail. It's bad news, but it doesn't mean all your data has to be lost.
"You can buy the hardware again, but often the personal data such as photos and messages are irreplaceable," says Manuel Fischer of the German IT association Bitkom.
"A backup is a copy of important data that is used to prevent data loss," explains Stephan Heuser, a researcher at the Technical University of Darmstadt in Germany.
Creating a backup is wise in case of theft or system failure and they're also used when setting up a new device to have the same data as an old one.
But which data is worth backing up?
"Private users should consider first of all personal contacts and calendar information, emails, important documents as well as personal photos and videos," says Heuser. Credentials for internet services should also be backed up in a secure manner.
"In the era of cheap USB sticks and terabyte hard drives, one can be generous when creating a backup," says Heuser. USB sticks or external hard drives are ideal for home users. "One should be aware, however, of the average life expectancy of backup media," Heuser said.
It's recommended that backups should not only be stored locally but should be geographically distributed - for example in a safe-deposit box or at the home of friends. Otherwise a house fire, for example, could destroy the PC, the smartphone and the tablet and the backup disc as well.
Cloud storage also has its advantages.
"Recovery from a hardware defect can occur anywhere - for example while on a business trip or on holidays, if the PC with the local backup is not available," says Manuel Fischer.
Katrin Borcea-Pfitzmann from the Institute for Computer Science at the Technical University of Dresden favours local backups over cloud backups in the interests of privacy. "Eavesdropping or data manipulation is much more difficult," she says.
The closest-to-hand cloud solutions are those of the equipment vendors themselves - iCloud for Apple devices, a Google account for Android and OneDrive for Windows phones.
"Whoever doesn't completely trust these firms can set up an account with an independent cloud platform like Dropbox. A solution where you can even operate your own server is My Cloud," says Borcea-Pfitzmann.
Smartphone and tablet manufacturers offer built-in options for local backups. For example, users of Android devices can use a Google account to back up their entire system in a process that runs in the background.
For Apple devices, backing up is done through iTunes, so backups can be carried out every time the iPhone or iPad is connected to the computer. In addition the user can decide whether they want to back up locally or to iCloud and whether they want the backup to be encrypted.
"Encrypted backups are always advantageous when confidential data such as messages or passwords are backed up. Especially when the backup is done in the cloud, encryption should be selected in every case," says Bitkom expert Fischer.
But make sure you don't forget the password if you use encryption. If you do forget, even an experienced service provider in data recovery won't be able to recover the data for you.