Final answer:
Clicking the show/hide button in the Home ribbon reveals hidden formatting marks in a document, assisting with layout and editing.
Step-by-step explanation:
When you click the show/hide button in the Home ribbon of a word processing program like Microsoft Word, it toggles the visibility of hidden formatting marks such as spaces, tabs, paragraph marks, and other non-printing characters. This button is usually represented by the symbol that resembles a backwards 'P' known as a pilcrow. Utilizing this feature can help users understand the layout and structure of their document more clearly, making it easier to adjust formatting and resolve spacing or alignment issues that are not readily apparent when these marks are hidden. Moreover, this visibility is crucial for precise editing and clean document formatting, especially for tasks that require a more advanced text alignment or precise placement of elements within a document.