RMSE stands for Root Mean Square Error. Fancy, huh? It punishes big mistakes hard—like a strict teacher. It takes all your errors, squares them, averages them, then yanks the square root back.
A lower RMSE means your predictions are tight. A higher one means your model is drunk on bad data. Either way, it’s drama for your spreadsheet.
Did you know RMSE is used in weather forecasting? Yes, meteorologists use it to see how wrong their “sunny” predictions are. Next time it rains on a sunny forecast, blame RMSE.
