Onsite backup support, also referred to as on-premise backup, is the process of backing up systems to a local disc, drive, or server. You can choose from media types as your backup target, depending on the data you need to protect.
External drives are convenient and inexpensive. You can back up to your external drives manually or continually, and most operating systems can be configured to automate the process. However, should you experience a major power surge or outage, you could lose your backup too.