To back up data on a Samsung device running Lollipop to a Samsung cloud, go to the Settings app, navigate to Accounts, tap Samsung Account, and tap More Options. From the options provided, tap Sync Now. Wait for the sync to complete. You can check Auto Backup so that your device automatically backs up your data once per day.
If the device is running KitKat or an earlier Android version, go to Settings, navigate to Accounts, go to Samsung Account, and tap Backup. Tap the checkboxes next to the items that you wish to backup, tap Backup Now, and wait for the backup process to run to completion.
You can also back up your data to a Google cloud. To do so on a device running Lollipop, go to Settings, scroll to Accounts, tap Google, and tap your Google email address. Tap More Options on the screen that appears, and then tap Sync Now. If your device is running KitKat or an earlier version of Android, go to Settings, go to Accounts, tap Google, and tap Email Address. Touch the checkboxes next to the items you want to synchronize, and then tap Sync Now.
For large files, such as music and videos, back up to a Dropbox account.