Letter-spacing is not the same as kerning, which alters the spacing of certain pairs of adjacent letters, such as "7," which would seem badly spaced if left alone. Letter spacing affects the overall size of a text string. Kerning involves adjusting the distance between two specific items in a document - usually two characters or glyphs that are to be rendered in close proximity to one another. There are several ways to adjust the spacing between characters without affecting their appearance: the user can change the device's font size, thereby changing the space between all words of a given size; or they can choose a different typeface with varying amounts of space between letters.