Fill may refer to any of the following:
1. When referring to computer graphics, fill describes to the process of changing a portion of an image to a color or pattern. For example, in most graphic programs a fill is done with the paint bucket tool. The picture is an example of an empty 'C' and 'H', with the 'C' filled with blue using the paint bucket tool.
2. When referring to a spreadsheet, fill is the process of copying several formulas or values from one cell to many cells.