When you delete a section break (section break: A mark you insert to show the end of a section. A section break stores the section formatting elements, such as the margins, page orientation, headers and footers, and sequence of page numbers.), you also delete the section (section: A portion of a document in which you set certain page formatting options. You create a new section when you want to change such properties as line numbering, number of columns, or headers and footers.) formatting for the text above it. That text becomes part of the following section, and it assumes the formatting of that section.
If you're in print layout view (Print Layout view: A view of a document or other object as it will appear when you print it. For example, items such as headers, footnotes, columns, and text boxes appear in their actual positions.) or outline view (outline view: A view that shows the headings of a document indented to represent their level in the document's structure. You can also use outline view to work with master documents.) and don't see the section break, display hidden text (hidden text: Character formatting that allows you to show or hide specified text. Microsoft Word indicates hidden text by underlining it with a dotted line.) by clicking Show/Hide on the Standard toolbar (toolbar: A bar with buttons and options that you use to carry out commands. To display a toolbar, press ALT and then SHIFT+F10.).