Wordmark: Brand name in a custom font (e.g. Google, Coca-Cola)
Lettermark: Initials of the brand (e.g. IBM, HBO)
Pictorial Mark: Icon or symbol (e.g. Apple, Twitter)
Abstract Mark: Geometric or abstract symbol (e.g. Nike)
Mascot: Character representing brand (e.g. Pringles)
Emblem: Text inside symbol/badge (e.g. Starbucks)