In Microsoft Excel, a worksheet is organized into a grid of columns and rows.
Columns are identified by letters (A, B, C, ... AA, AB, ...).
Rows are identified by numbers (1, 2, 3, ...).
The address or reference of a specific cell is determined by combining its column letter and row number.
The standard convention for a cell reference is to write the column letter first, followed by the row number.
For a cell located in column A and row 4, the correct reference is A4.