The ribbon bar at the top of the Microsoft Word screen is very crowded. There’s a good chance that you’ve clicked only on a small percentage of the symbols and words up there.
Many of them won’t help you, but the backwards “P” can be very useful. It’s called a pilcrow, and normally indicates the beginning of a paragraph.
If you click on the pilcrow icon, the text on your screen will change greatly, revealing formatting indicators for such items as spaces between words and section breaks as shown below.
The sample reveals an extra space before the word “spaces” that might not be visible on a normal page.
The pilcrow icon’s “show/hide” function will probably reveal problems every few pages that you would not have otherwise noticed and will help you make a better book.
While editing, you should take advantage of Pilcrow Power. However, the extra indications can be annoying and fatiguing during regular reading—so tap the icon to shut off Pilcrow Power when you don’t need it. Also, when PIlcrow Power is in effect, your document will expand and the page numbering will temporarily change.
(from my book, Self-Editing for Self-Publishers (What to do before the real editor starts editing -- or if you're the only editor). It's an Amazon Kindle ebook, readable on many e-reading devices, including computers. You don't need to own a Kindle to read it.)