A style is a set of formatting rules that apply to text, tables, and lists in a Word document. When a style is applied it can change the appearance and structure of a document quickly. To view styles, click the launcher from the styles pane (see below).
Learn to use styles! So many Word users manually adjust section by section and implement formatting the direct method instead of using styles. The author is guilty of this just as well. Advantages of styles include speed, format consistency, ability to insert a table of contents, and ease of updating. Styles are granular. They encompass these levels: paragraph, character, table, and list.
Use the style inspector button to open a panel which will display the paragraph and text formatting details. Once this window is open you can modify a style by right-clicking it and choosing Modify.
From Modify Styles you have the option to change the font, paragraph spacing, and far more via the Format button in the lower left. An example is numbering which controls the look and style of outlining for just this level..
Should you want to modify all the numbering of a document you would want to create a new list style by clicking on the multilevel list button drown down and selecting Define New List Style. Give it a name and click the Format button in lower left. Now you can adjust each level.