Provides electricity to equipment in case a power failure occurs. Just as computing devices are continually scaling up, UPS devices have also become updated. In fact, it has only been after the 1980s that vendors began realizing the business potential in this space. The 1980s was a decade dominated by mainframe computers and numerous power blackouts, a problem managed through stand-by generators. Though the generators kept key systems up and running, the majority of terminal users were denied access. This less-than-perfect scenario was the catalyst for the emergence of defined segments in the UPS space.

During the late 1980s, the stand-alone PC backups came into being, sparking the growth of a totally new market. Today, stand-alone UPS devices of various capacities have become a default peripheral device bundled with every desktop computer.

Although UPS continues to provide electricity to equipment during power failures, there are less-than-perfect security policies for fail-open and fail-close. In fact, by causing devices to fail—by cutting off power—crackers can get easy access to supposedly secure systems. For example, for safety reasons, automatic doors are commonly left open when power fails to prevent individuals from getting caught inside. Likewise, some firewalls are configured with bypasses to permit access when power failure to the firewall occurs.

See Also: Computer; Firewall.