What type of reference allows you to keep a row or column constant in a formula?

An absolute reference allows you to keep a row or column constant in a formula by using the dollar sign ($) before the column letter and/or row number. This means that when you copy the formula to another cell, the reference does not change. For example, if you have a formula that refers to $A$1, both the column A and the row 1 remain constant no matter where the formula is pasted. This is particularly useful when you want to refer back to a specific cell for calculations, such as constants or fixed values, without having those references shift as the formula is moved to different locations within the spreadsheet.

In contrast, a relative reference changes based on the position of the cell where the formula is copied, while a mixed reference means that either the row or the column is fixed while the other is relative. Dynamic references, while they can adjust based on data changes or conditions, do not specifically control the constancy of rows or columns as absolute references do.