A tab stop is a term used to describe the location the cursor stops after the Tab key is pressed. Tab stops are used in word processors to enable users to align text by pressing the Tab key. Below is a picture of the ruler bar in Microsoft Office with each of the left tab stops marked as bold L's. If these were right tabs, the L would be backwards. In Microsoft Word, the tab selector, also called the tab indicator, is a button to the left of the ruler that supplies the user with a variety of tab marker options.