Signal-to-noise ratio (SNR) measures the level of a desired signal (useful information) relative to the background noise (unwanted interference). Expressed in decibels (dB), a higher SNR means a clearer, more accurate transmission or recording, as there is more signal and less static or distortion.

SNR is an important parameter that affects the performance and quality of systems that process or transmit signals, such as communication systems, audio equipment, radar systems, imaging systems, and data acquisition systems. A high SNR means that the signal is clear and easy to detect or interpret, while a low SNR means that the signal is corrupted or obscured by noise and may be difficult to distinguish or recover. SNR can be improved by various methods, such as increasing the signal strength, reducing the noise level, filtering out unwanted noise, or using error correction techniques.

(Source: Wikipedia Commons)