Selector Type Efficiency There are four main types of selectors in CSS–ID, class, tag and universal. IDs are unique elements denoted by the hash, like our old friend #current.

Ryan Boudreaux covers the basics about CSS specificity hierarchy in an effort to make this tricky concept easier to understand.

The selectors indicate the elements that styles are applied to in the markup. One of the easiest ways to get started with CSS is to understand the core selectors, child selectors and descendant ...

Google's John Mueller was asked if Google "looks at "CSS .Class" to comprehend the structure of a page; or a section of content that clarifies its SERP Features." John responded on Twitter saying ...