Explanation:
Using references in formulas
A reference identifies a cell or a range of cells on a worksheet, and tells Excel for the web where to look for the values or data you want to use in a formula. You can use references to use data contained in different parts of a worksheet in one formula or use the value from one cell in several formulas. You can also refer to cells on other sheets in the same workbook, and to other workbooks. References to cells in other workbooks are called links or external references.
