One of the biggest advantages of having online backups is that you can access your files from anywhere, at any time. Most online backup providers let you view and download files from a web browser and mobile apps, but that should be the bare minimum. Many also include file-sharing options, the best of which even let you specify a password for access and an expiration date for the shared item.

The quality and utility of mobile apps vary widely. Some just offer simple document and media file downloads from your existing backups, but the most feature-complete options let you back up data on your mobile devices and even remotely control backups on other systems.

The concept behind backup software is pretty simple: You make a copy of your files on storage separate from your main hard drive. That storage can be another drive, an external drive, a network-attached storage device (NAS), a rewritable disc, or the cloud—meaning someone else's servers. Should you lose your local files, either through disaster or simply by deleting or overwriting them, you can just restore them from the saved copy.

For this to work, the copies of your files must be updated regularly. Most backup solutions let you schedule scans of your hard drive for new and changed files daily, weekly, monthly, or continually (or at least every 15 minutes or so). Typically, you also have the option to instruct the backup service to monitor your drive for newly created or changed files to back up as they occur.

More granular options include whether backups are full, incremental, or differential. A full backup is when all the information you've selected for backup is copied in its entirety. Incremental backup saves system resources by backing up only the changes in files since the last incremental backup. Differential backup saves all changes from the last full backup. With incremental backups, you need the latest full backup and all the intermediary backup data to restore a file to its original state, whereas with differential backup, all you need is the last set of differential backup data and the first full one.

IDrive is the best Android backup app for a swift backup of app data, photos and videos. It comes with an excellent UI and easily configurable automatic backups.