When you insert a row or column in Excel, you are essentially adding a new cell or group of cells to your worksheet. This can be done by selecting the cell or group of cells where you want the new row or column to be inserted, and then clicking on the Insert option in the Home tab. You can also right-click on the selected cell or group of cells and choose Insert from the menu that appears.
If you want to insert more than one row or column at a time, you can select the number of rows or columns that you want to insert from the Insert drop-down menu. For example, if you want to insert two columns, you would select 2 Columns from the menu. You can also use this menu to insert cells, rows, or columns that are shifted over from another location in your worksheet.
Once you have selected where you want to insert the new row or column, and chosen how many rows or columns to insert, Excel will add the appropriate number of cells at the insertion point. If there were any cells in the way of where the new cells are being inserted, they will be shifted over to make room for the new cells.