Answer Description
True - failure of a single disk in RAID 1 will NOT result in permanent data loss. Redundant Array of Independent Disks 1 (RAID) uses disk mirroring to ensure every piece of data can also be found on another hard drive. This means if a single disk fails, another disk will still have the necessary data.
Wikipedia
RAID ( "Redundant Array of Inexpensive Disks" or "Redundant Array of Independent Disks") is a data storage virtualization technology that combines multiple physical disk drive components into one or more logical units for the purposes of data redundancy, performance improvement, or both This was in contrast to the previous concept of highly reliable mainframe disk drives referred to as "single large expensive disk" (SLED)Data is distributed across the drives in one of several ways, referred to as RAID levels, depending on the required level of redundancy and performance The different schemes, or data distribution layouts, are named by the word "RAID" followed by a number, for example RAID 0 or RAID 1
RAID - Wikipedia, the free encyclopedia