When you're editing content in Microsoft Office you're in one of two basic modes: Insert or Overtype
- Insert mode is what you're used to. As you type, any characters to the right of what you're typing move over to make room for your new text.
- When you are editing text in overtype mode, you are typing text over your previous text. In this mode, typing new characters replaces any existing characters to the right side of the insertion point.