Normally when it comes to horizontal alignment, Excel either automatically sets the first character of the entry flush with the left edge of the cell (the left alignment default for all text entries) or the last character of the entry flush with the right edge (the right alignment default for all numeric entries). If you center a data entry (by clicking the Center button on the Formatting toolbar), Excel attempts to make the space between the left edge and the first character in the entry equal to the space between the last character and the right edge.

Instead of relying on centering to set off particular entries in a worksheet, many times you can just indent the entries from the left edge to set them off from the others. For example, a sales table that contains sales figures for three kinds of recording media: CDs, cassette tapes, and LPs. Each of these three groups has it own subheadings that list the same four music categories (Rock, Jazz, Classical, and Other). You can improve the legibility of the row headings for this table by indenting these category subheadings.

To do this, you could just select all the ranges with the subheadings as a single cell selection and then click the Increase Indent button on the Formatting toolbar. However, if you want to indent the headings more than a single character (which is the default when you click the Increase Indent button), you're better off doing this from the Alignment tab of the Format Cells dialog box.