In one sentence, describe what the following article is about:

Simply double-click an Excel document to open it in Excel. Doing so will select it, allowing you to type into it. This command indicates that you want to multiply items together. This should be the cell at the top of the range of data. For example, you might type "A1" here. . The colon symbol (":") indicates to Excel that you want to multiply everything from the first cell through the next cell you enter. This cell must be in the same column or row as the first cell in the formula if you want to multiply all the cells from the first cell to this one. In the example, typing "A5" would set up the formula to multiply the contents of A1, A2, A3, A4, and A5 together. This last parenthesis closes the formula, and hitting enter runs the command and multiplies your range of cells together, displaying the result instantly in your selected cell. If you change the contents of a cell within the multiplication range, the value in your selected cell will also change.

Summary:
Open an Excel presentation. Click a cell. Type =PRODUCT( into your cell. Type in the first cell's name. Type  : Type in another cell's name. Type ), then press ↵ Enter.