A class can be used more the once. You're not supposed to give multiple elements the same ID ...

I'm trying to move to CSS only, however I have a couple of stumbling blocks to overcome. First, what's the difference (advantages?) of using CSS id vs CSS class (#content vs .content for instance ...

The use of classes is also very common when creating webpages. Classes operate in a similar way to element IDs but rather than relating to the id of an individual element, styles for a class can ...

Ryan Boudreaux continues his tutorial on getting acquainted with jQuery by showing you how to get objects by ID and Class selectors and by Tag and Attribute.

When both the Class and ID are applied to the section as coded in the HTML displayed above, the ID selector wins out since it has a specificity value of 0,1,0,0, and the Class selector has a value ...