I think you’re referring to the “Create a Class to Target with jQuery Selectors” lesson in the Bootstrap section of Front End Development, correct?
Not every class needs to have corresponding CSS. Sometimes we create classes just for the purpose of selecting these elements more easily using jQuery.
Give each of your button elements the class target.
I assumed that this target class would be used later in the jQuery section, but I couldn’t find where the targetclass was being used, only target#id’s. I’m curious about this too.
I cannot say for sure, but often a class is assigned to some element - in this case a button - to hook it into a framework, a plugin, or some other library of code. In this specific case the class btn and btn-default look like Bootstrap, so maybe it is hooking the button to that.