THE SPACES BETWEEN LETTERS are as important as the letters themselves. Kerningand its cousin trackingare ways of adjusting the space between characters to create a better fit, and thus a better rhythm, to your type. It's this steady rhythm that makes your type readable.
We need kerning because certain letter shapes don't fit well together. Sometimes it's necessary to adjust the space between letters to achieve the appearance of even spacing.
A surefire way to raise the hackles of a purist typographer is to use the terms kerning and tracking interchangeably. While closely related, they are distinct. Kerning refers to adjusting the space between a pair of characters. Tracking means adjusting the space across a range of text.
When to Kern
Part I: Character Formats
Going with the Flow
Getting the Lead Out
Kern, Baby, Kern
Sweating the Small Stuff: Special Characters, White Space, and Glyphs
OpenType: The New Frontier in Font Technology
Part II: Paragraph Formats
Aligning Your Type
Paragraph Indents and Spacing
First Impressions: Creating Great Opening Paragraphs
Dont Fear the Hyphen
Mastering Tabs and Tables
Part III: Styles
Stylin with Paragraph and Character Styles
Part IV: Page Layout
Setting Up Your Document
Everything in Its Right Place: Using Grids
Text Wraps: The Good, the Bad, and the Ugly