A paragraph is, for the writer, a discrete part that is about a core idea. In Word it is some text followed by a paragraph mark. It ought to be a logical paragraph as well. The paragraph in Word is one of those containers I was talking about. The paragraph mark in Word carries a number of formatting commands for the paragraph. I believe the count is about fifty different things that a paragraph mark can contain about the text that comes between it and the beginning of the paragraph.

The simplest (least data-intense) paragraph marks are those that simply tell Word which paragraph Style is to be used for formatting. Essentially it is a reference to Word to "look here" to the style definition to decide what formatting is to be applied to the paragraph.

If you use paragraph marks to add vertical space in a document, you are misusing them. You are adding complexity to your document file. This makes for more effort to edit it. For Word, it requires more effort, more processing, to print or display. This can contribute to document corruption, a document becoming unusable.

Basic concepts of Microsoft Word: An introduction by Shauna Kelly