CSS works in combination with HTML. We can create buttons, links, and other elements using HTML and then using CSS we can change those elements’ size, color, position, etc.

This question leads to one of the most important ideas behind CSS: The selector, so named because it’s the way we “select” the HTML we want to style.

CSS selectors are patterns used to select Web site elements to be styled in various ways, including some 500 properties for color, fonts and so on. While basically universally required in Web ...