Noise:
The noise is the component of the observed data (e.g. of a time series ) that is random and carries no useful information. The presence of noise is often the major nuisance factor that makes statistical inference from the data more difficult. The complementary concept is signal .
The concept of noise, along with the concept of signal , is the basic concept in signal processing , image processing and many branches of the time series analysis .
See also: signal processing .