In Excel, there are two ways to reference an entire column or row:

1. Using the column letter or row number:

* Entire Column: Simply use the column letter (e.g., A, B, C) to reference all cells within that column.
* Entire Row: Use the row number (e.g., 1, 2, 3) to reference all cells within that row.

Examples:

* A: Refers to all cells in column A (from A1 to the last used cell in that column).
* 5: Refers to all cells in row 5 (from A5 to the last used cell in that row).

2. Using Colons (:)

* Entire Column: Use the column letter followed by a colon (:) to reference all cells within that column.
* Entire Row: Use the row number followed by a colon (:) to reference all cells within that row.

Examples:

* A:A: Refers to all cells in column A (from A1 to the last used cell in that column). This is functionally the same as using just the column letter (A).
* 5:5: Refers to all cells in row 5 (from A5 to the last used cell in that row). This is functionally the same as using just the row number (5).

Additional Notes:

* To reference a range of columns or rows, you can combine these methods. For example, B2:D10 refers to the range of cells starting from B2 and ending at D10.
* By default, these references are relative, meaning they will adjust if you copy the formula to another cell. You can use absolute references by pressing F4 after entering the cell address to lock the specific column or row (e.g., $A$1).