Each worksheet starts out with several styles in its style list,
depending on the number of styles defined in the template used.
Any number of styles can then be added.
There are several ways in which you can change the appearance or type of cells. You can either:
Alter the existing style so that all the cells in that style in the worksheet are changed. (Editing styles)
Add a new style to the list, and apply it to the selected parts of the worksheet, layering the new style over the original one. (Adding a new style)
Apply an existing style or styles to the text or numbers.