What is Redundancy:
A redundancy may be repetition or repeated use of a word or expression to express an idea, as well as excess or excessive abundance of anything. The word, as such, comes from Latin redundant.
Redundancies, in language, are ways of expressing things by repeating or reiterating certain words, ideas or concepts, in order to emphasize the message you want to convey. It is, as such, an expressive resource, but it can lead to tautology.
In information theory, redundancy is considered to be a property of messages according to which, thanks to the existence of repetitions or predictable parts that do not actually provide new information, the rest of the message can be inferred. It is, above all, a fundamental communication strategy to avoid misunderstandings or errors in decoding.
Synonyms of redundancyFor their part, they can be abundance or surplus, or repetition, reiteration or pleonasm. Antonyms would be scarcity or parsimony.
Redundancy in rhetoric
In rhetoric, redundancy is a literary figure called pleonasm. It is characterized by not adding new information to the message that is to be transmitted, but rather by insisting or emphasizing some part of said message.
Examples of redundancies:
Go upGo downGo outRepeatEyewitnessFly through the airClearly obviousThe cold ice
See also Pleonasm.
Redundancy in computer systems
In the field of computing and systems, redundancy is the simplest means of having a highly available system or, in other words, a backup.
The redundancy of network interfaces, computers, servers, internal power supplies, etc., allows a system to remain in perfect working order in the event of failure of any of its components.
An example of redundancy would be the repetition of data contained in a database. Thus, in case of any failure, the data would not be lost.
See also Tautology.