Excel Cell References
Excel Cell References explains how columns, rows, and individual cells get their names, and the difference between relative, absolute, and mixed references in formulas.
How Cells Are Named
Every cell address combines its column letter with its row number, always in that order: column first, then row. The cell in column C, row 4, is named C4. The cell in column A, row 1, is named A1, and it sits in the very top-left corner of the worksheet.
The Name Box
The Name Box, just above column A, always shows the address of whichever cell is currently active. You can also type a cell address into the Name Box and press Enter to jump straight to it, which is handy on very large worksheets.
Relative References
By default, references are relative, meaning they describe a position compared to the formula's own cell. If you copy a formula from one row to another, the row numbers inside it shift to match, which is exactly what you want when applying the same calculation down a column.
Example
=A1+B1Absolute and Mixed References
Sometimes you need part of a reference to stay fixed no matter where a formula is copied, for example when every row should multiply by the same tax rate cell. Adding a dollar sign before the column letter, the row number, or both, locks that part in place. $A$1 locks both the column and row (absolute), $A1 locks only the column, and A$1 locks only the row (both are mixed references).
Example
=$A$1+B1
