What is the difference between id and class in CSS, and when should I use them? [duplicate]

Answer 1

ID's have the functionality to work as links to particular sections within a webpage. a keyword after # tag will take you to a particular section of the webpage. e.g "http://exampleurl.com#chapter5" in the address bar will take you there when you have a "section5" id wrapped around the chapter 5 section of the page.