Styles in Word 2016 are applied to text just like any other formatting: Select a block of text and then apply the style or choose the style and start typing. The big difference between a style and an individual format is that the style contains multiple formats, applied all at once.
As you hover the mouse pointer over a style in the Style Gallery, text in the document is updated with a style preview.
Some styles are assigned a keyboard shortcut. For example, the shortcut for the Normal style is Ctrl+Shift+N. Use the keyboard shortcut to apply the style.
Heading styles play a special role in Word. They're used for document navigation, outlining, as well as creating a table of contents.
As with any other formatting, applying a style replaces the text's previously applied style.