The ¶ mark in Word is the single most powerful character in your document. All of the paragraph formatting that you apply to your document is ‘contained’ in the ¶. To see the ¶ marks throughout your document, you should always have the Show/Hide button activated in Word. (The Show/Hide command is circled in red below–when activated it will appear in yellow.)
Experiment in a Word document: type a sentence and hit the ENTER key. (Make sure Show/Hide is active.) Then click into that sentence anywhere–no need to select the sentence or any part of it. Apply a formatting command such as left justify (the box that is highlighted in yellow in the graphic). The entire sentence (or sentences) before that ¶ will follow the formatting command.
But, I hear you object: “I did what you said and hit B (for bold) and everything did not bold.” That’s because the ¶ command does not control character formatting such as bold or italic. Here’s a rule of thumb: anything in the Paragraph section on the Home tab is controlled by the ¶. Anything in the Font section of the Home tab is considered character-level formatting and you should apply it, at most, to a word or two at a time. If you want to apply it more widely, you should use a Style Sheet, which I will cover in an upcoming post.
Remember, if you do nothing else in Word, turn on Show/Hide. It will make your life a lot easier. And with all that extra time, you can go wrestle the alligators in the Back 40.