What type of clause is "the grand canyon is a stunning sight" ? such as in the sentence "the grand canyon is a stunning sight, but yosemite national park also has many impressive features that you will never forget"

Suppose you need to verify how to correctly use commas. you open your english textbook and scan the chapter titles. in which one would you most likely find the information you need? ; ; ; ; that's the ? im having truble with