SUMIFS is an Excel function, introduced with Excel 2007 (v12.0), which allows for the summation of values selected according to several criteria – addition is only of cells meeting all the conditions.
Microsoft describes the syntax so:
SUMIFS(sum_range, criteria_range1, criteria1, [criteria_range2,criteria2], …)
AbleBits compares SUMIFS and SUMIF and gives examples of usage. Between the two the position of sum_range differs and for SUMIFS each criteria_range must contain the same size (number of rows and columns) as the sum_range argument.