A cell reference or relative cell reference describes how far away a cell or group of cells is from another cell in the same spreadsheet. When dealing with a spreadsheet formula, the relative cell reference is the default behavior of a formula. For example, to add cells A2 and B2 together you could use the formula "=SUM(A2+B2)" in cell C2, and if you were to copy that formula into cell C3, it would be relative to C3 and become "=SUM(A3+B3)."