Dictionary:Background

{{#category_index:B|background}} 1. Average noise level, whether systematic or random, upon which a desired signal (such as a reflection) is superimposed; ambient. Usually refers to the total noise independent of the presence of the signal. Occasionally refers to an overall pattern upon which an anomaly is superimposed. 2. A computer operation going on while some other computer operation is underway. For example, a computer might be printing in the background while an operator is word processing.