Final answer:
The Mailings tab in Microsoft Word is designed for preparing envelopes and labels, providing tools for formatting and printing.
Step-by-step explanation:
The tab in Microsoft Word that helps you prepare envelopes and labels is the Mailings tab. When you need to create and print envelopes and labels, you can locate this tab at the top of the Word document interface, among other tabs like Home, Insert, and Page Layout. Once you click on the Mailings tab, you will find a variety of tools specifically for setting up envelopes and labels, including options for formatting, specifying recipients, and choosing printing options.