What is meant by signal to noise ratio

[Yash-papa]

I need a definition signal to noise ratio. I am trying to find it out on internet but am unable to find the same. I know it is some thing about electrical engineering measurement but i want to understand it properly.

I appreciate your help in advance. Please help.

[Dodger]

A ratio of desired signal to undesired signal (noise) in the average power level of a transmission is defined as the Signal to Noise Ratio which is also know as SNR in short. It is a calculated value that represents the ratio of rms signal to rms noise.A higher ratio indicates higher sound quality (less noise). Most transmission techniques try to minimize noise on the receiving end of the transmission.In less technical terms, signal-to-noise ratio compares the level of a desired signal to the level of background noise. The higher the value of SNR, the better will be the signal strength and the quality of transmission.