Signal-to-noise plus interference

Imagine you are trying to hear someone speak while you are standing in a busy and noisy park. The person's voice is the signal, the park noise is the noise, and if a group of people starts singing loudly, that is interference.

In the same way, when we talk about signal-to-noise plus interference, we mean that something is trying to send a message (a signal), but there are other sounds (noise) or signals (interference) getting in the way.

For example, when you watch TV, your signal is the TV show that you want to watch. The noise is any static or distortion you see on the screen. And interference could come from another TV station broadcasting at the same time, making it difficult for your TV to receive a clear signal.

So, the signal-to-noise plus interference ratio is the amount of the useful signal compared to the unwanted noise and interference. We want a strong signal and as little noise and interference as possible to make it easy to understand and enjoy what we are trying to hear or see.