Tracking creates an even spacing between multiple characters in a line of text, widening it out, or tightening it up. Kerning adjusts the width of the space between two characters in a line of text.
The Character Palette Explained Adobe Illustrator / Getting Started
Chances are you have used the Character Palette at some point in Adobe Illustrator but are you getting the most out of it? Learn everything you need to know about Adobe Illustrator's Character Palette including leading, tracking, kerning, baseline shift, and more.