Cell addresses in Excel are identified using a combination of a column letter and a row number. This unique code specifies the exact location of a cell within the worksheet.

* Columns: Columns are labeled with letters, starting from A and continuing alphabetically all the way to XFD (a very large spreadsheet!).
* Rows: Rows are numbered, starting from 1 and going down indefinitely.

Here's an example:

* Cell A1: This refers to the cell at the intersection of the first column (A) and the first row (1).
* Cell C5: This refers to the cell in the third column (C) and the fifth row (5).

By understanding this system, you can easily pinpoint any cell on your spreadsheet and use its address in formulas or other Excel functionalities.