A tab stop on a typewriter is a location where the carriage movement is halted by an adjustable end stop. Tab stops are set manually, and pressing the tab key causes the carriage to go to the next tab stop. In text editors on a computer, the same concept is implemented simplistically with automatic, fixed tab stops.
Modern word processors generalize this concept by offering tab stops that have an alignment attribute and cause the text to be automatically aligned at left, at right or center of the tab stop itself. Such tab stops are paragraph-specific properties and can be moved to a different location in any moment, or even removed.
A tab stop is a horizontal position which is set for placing and aligning text on a page. There are at least five kinds of tab stops in general usage in word processing or in MS Word.
Some software supports tab stops whose positions are set dynamically by the position of a specific character in a line of text. Adobe InDesign supports this with a non-printing "indent to here" character. Third-party plug-ins add this functionality to numerous other programs including Visual Studio, and Go's tabwriter package.