If I have a number (from a sequence) and I then subtract that number from the average of that sequence- what do I have? I would describe it as a 'deviation from the average' - but is there a better term for this?
For example - If I add all numbers in a sequence and divide them by the count of the numbers in the series I get an average.
These deviations are usually called the errors or residuals. (The distinction between these two terms becomes important if your sequence is a sampling from a probability distribution, in which case error is measured with respect to the true mean instead of the sample mean.)