A "Read More" break is a way to define the intro text that displays for items on a page with several items like Staff or Blog. For example, if you have a staff page where the person's name, title and phone number displays, and then you click their item to show that information along with a full bio. Here's a help doc on adding Read More breaks, and this page gives instructions on adding staff pages specifically. Note: not all sites use these, if you want to be able to define intro text to display your blog or other pages differently, please let us know.