CSS consists of selectors and properties. Selectors are the part of CSS that allows you to target specific elements on a web page and apply rules to them. For example, the p selector will apply a rule to all paragraphs on a web page.You can use the properties and selectors to style any element on a web page. For example, you can use the color property to change the color of an element's text and the font-family property to change the font of an element's text.The most important thing to remember about CSS is that it is a language for describing the content presentation. It is not a programming language, and you can’t use it to create interactive web pages.