In
engineering,
redundancy is the duplication of critical
components of a system with the intention of increasing reliability of the
system. In safety-critical systems, such as
fly-by-wire aircraft, some parts of the control system may be triplicated. An error in one component then may then be out-voted by the other two. See
safety engineering.
In
information theory,
redundancy is the number of bits used to transmit a message minus the number of bits of actual information in the message.
Data compression is a way to eliminate such redundancy.
See also: