There are two types of cell references that you can use in a formula:

1. Relative (example: A:13)
2. Absolute (example: $A:$13)

In a relative cell reference, the reference changes when you copy a formula containing the cell reference.

In an absolute reference, the cell references will not be changed. A cell reference can be made absolute by typing a dollar sign ($) before the column letter and row number in the cell reference.