In typography, letter-spacing, usually called tracking by typographers, refers to a consistent degree of increase (or sometimes decrease) of space between letters to affect density in a line or block of text.

Letter-spacing should not be confused with kerning. Letter-spacing refers to a uniform adjustment to the spacing of a word or block of text affecting its density and texture. Kerning is a spacing adjustment of one or more specific pairs of adjacent characters that, because of the relationship of their respective shapes, would appear to be badly spaced if spaced normally. A classic example is a capital V next to a capital A, which need to be brought closer together.