What does the term 'RAID' stand for?

user warning: Unknown column 'e.has_time' in 'field list' query: SELECT e.event_start, e.event_end, e.timezone, e.has_time, e.has_end_date, tz.offset AS offset, tz.offset_dst AS offset_dst, tz.dst_region, tz.is_dst, e.event_start - INTERVAL IF(tz.is_dst, tz.offset_dst, tz.offset) HOUR_SECOND AS event_start_utc, e.event_end - INTERVAL IF(tz.is_dst, tz.offset_dst, tz.offset) HOUR_SECOND AS event_end_utc, e.event_start - INTERVAL IF(tz.is_dst, tz.offset_dst, tz.offset) HOUR_SECOND + INTERVAL 0 SECOND AS event_start_user, e.event_end - INTERVAL IF(tz.is_dst, tz.offset_dst, tz.offset) HOUR_SECOND + INTERVAL 0 SECOND AS event_end_user, e.event_start - INTERVAL IF(tz.is_dst, tz.offset_dst, tz.offset) HOUR_SECOND + INTERVAL -25200 SECOND AS event_start_site, e.event_end - INTERVAL IF(tz.is_dst, tz.offset_dst, tz.offset) HOUR_SECOND + INTERVAL -25200 SECOND AS event_end_site, tz.name as timezone_name FROM event e INNER JOIN event_timezones tz ON tz.timezone = e.timezone WHERE nid = 23 in /home1/riddlede/public_html/sandboxbeta/includes/database.mysql.inc on line 172.

RAID stands for Redundant Array of Independent Disks. RAID generally refers to a storage system composed of multiple hard drives sharing or replicating data amongst themselves.