From the introduction:
Expert Classes. Three Classes appear in this document, each one a member of the Expert Group: the Bard, the Ranger, and the Rogue. Each Class appears with one Subclass. More Subclasses will appear in Unearthed Arcana in the months ahead.
Feats. Feats follow the Class descriptions, particularly feats available to the classes in this document.
Spell Lists. Three Spell lists—the Arcane, Divine, and Primal lists—are featured here. The Ranger uses the Primal list, and the Bard potentially uses all three, thanks to the Magical Secrets feature.
Rules Glossary. In this document, any term in the body text that is underlined appears in a glossary at the end. The glossary defines game terms that have been clarified or redefined for this playtest or that don’t appear in the 2014 Player’s Handbook.