Encryption is a complex mathematical algorithm used to protect and obscure information from unauthorized parties.

Firewalls are network devices or host based software designed and configured to restrict the access of external sources from internal hosts.

Hard Drive Redundancy
A redundant hard drive setup consists of multiple hard drives in a specific configuration called a RAID. There are different RAID levels that provide different benefits. These benefits range from improved speed, to protection from drive failure.

A reference to a friendly/associated device or workstation.

RAID is an acronym for Redundant Array of Independent Disks, raid configurations provide protection against hardware failures, minimize downtime in the event of a hard drive failure and protect against events that could cause complete loss of data for an organization. Other configurations provide improved speed or consolidated storage space.

Redundant Backup
A typical redundant backup would consist of a full backup every day for the course of a month making a seperate copy for each day. In the event of a compounding failure one then has the option to restore the backup from up to 30 days previous.