PDF (adobe.com)

Set spacing between lines and letters

Kerning increases or decreases the spacing (in percentages) between certain pairs of letters to improve their appearance. Auto-kerning uses a font's kerning information when displaying text.

To disable auto-kerning, deselect Auto Kern in the Property inspector.

Leading determines the distance between adjacent lines in a paragraph. Leading can be measured in pixels or as a percentage of the distance, in points, separating the lines baseline to baseline.