Redundancy, in general terms, refers to the quality or state of being redundant, that is: exceeding what is necessary or normal; or duplication. This can have a negative connotation, especially in rhetoric: superfluous or repetitive; or a positive implication, especially in engineering: serving as a duplicate for preventing failure of an entire system.

The term redundancy is used, with variations on the above meanings, in the following fields:

• Redundancy (user interfaces)
• Database normalization, the elimination of redundancy in databases
• Redundancy (engineering)
• Data redundancy
• Redundancy (information theory)
• Redundancy (language)
• Redundancy (law), a reason for dismissal of an employee in the United Kingdom
• Redundancy (total quality management)

Redundanz | Redondance | Redundancia | Ridondanza | Redundantie | Redundancja | Redundans