(tab, Control-I, HT, ascii 9) A character which when displayed or printed causes the following character to be placed at the next "tabstop" - the column whose number is a multiple of the current tab width. Commonly (especially in Unix(?)) the tab width is eight, so, counting from the left margin (column zero), the tab stops are at columns 8, 16, 24, up to the width of the screen or page.

A tab width of four or two is often preferred when indenting program source code to conserve indentation.

Represented as "\t" in c, unix, and derivatives.