Style and Format are pre-defined combinations of various formatting options that make it easier to keep the presentation of the text uniform. They often contains a number of features at once; such as the font, or size, or text color, or background color, or different combinations of the previous.
Paragraph (Block) Format
A paragraph format can only be applied to a block-level element, like a paragraph or a div element. To choose a paragraph format, place the cursor inside the block-level element and press the toolbar button. The Format drop-down list contains a number of pre-defined block-level styles that you can use. To make the choice easier, the format names are displayed in a format that they represent, giving you a preview of what the text will look like: