In Google Sheets, the SUMIFS function is used to calculate the sum of a range of cells that meet multiple criteria. The function syntax is as follows:

SUMIFS(sumrange, criteriarange1, criterion1, [criteria_range2, criterion2, …])

"sumrange" refers to the range of cells that you want to sum if they meet all the specified criteria. "criteriarange1" is the range of cells that you want to evaluate for the first criterion. "criterion1" specifies the condition or criteria that the cells in "criteriarange1" must meet. [Optional] You can add more pairs of "criteriarange" and "criterion" parameters to evaluate additional criteria. Here's an example to demonstrate the usage of the SUMIFS function:

Suppose you have a dataset with three columns: A (contains numbers), B (contains categories), and C (contains regions). You want to calculate the sum of numbers in column A that meet certain category and region criteria.

In cell D1, you can use the formula:

=SUMIFS(A:A, B:B, "Category A", C:C, "Region X")

This formula will sum all the values in column A where the corresponding cells in column B match "Category A" and the cells in column C match "Region X".

You can include more pairs of "criteria_range" and "criterion" parameters to add additional criteria. The SUMIFS function allows you to perform calculations based on multiple conditions within a dataset.