multiple computers, servers or Network Attached Storage appliances on a local area network from a single computer or device. Continuous backup - Continuous Data Protection Allows the service to back up continuously or on a predefined schedule. Both methods have advantages and disadvantages. Most backup services are schedule-based and perform backups at a predetermined time. Some services provide continuous data backups which are used by large financial institutions and large online retailers. However, there is typically a trade-off with performance and system resources. File-by-File Restore The ability for users to restore files themselves, without the assistance of a Service Provider by allowing the user select files by name and/or folder. Some services allow users to select files by searching for filenames and folder names, by dates, by file type, by backup set, and by tags. Online access to files Some services allow you to access backed-up files via a normal web browser. Many services do not provide this type of functionality. Data compression Data will typically be compressed with a lossless compression algorithm to minimize the amount of bandwidth used. Differential data compression A way to further minimize network traffic is to transfer only the binary data that has changed from one day to the next, similar to the open source file transfer service Rsync. More advanced online backup services use this method rather than transfer entire files. Bandwidth usage User-selectable option to use more or less bandwidth; it may be possible to set this to change at various times of day. Off-Line Backup Off-Line Backup allows along with and as part of the online backup solution to cover daily backups in time when network connection is down. At this time the remote backup software must perform backup onto a local media device like a tape drive, a disk or another server. The minute network connection is restored remote backup software will update the remote datacenter with the changes coming out of the off-line backup media . Synchronization Many services support data synchronization allowing users to keep a consistent library of all their files across many computers. The technology can help productivity and increase access to data. Common features for business users Bulk restore A way to restore data from a portable storage device when a full restore over the Internet might take too long. Centralized management console Allows for an IT department or staff member to monitor and manage