Serial Correlation a.k.a. Autocorrelation

Serial Correlation, or Autocorrelation, is a statistical measure of the degree of similarity between a given set of values and a lagged version of itself. It measures the degree of correlation between the two versions, and identifies if there is any pattern in the data or if it is random. In other words, serial correlation measures how closely related a set of values are to lagged versions of itself. This can help researchers identify patterns in a time series data that could signal something occurring regularly over time.