Cascading Style Sheets (CSS) is a style sheet language that permits web designers to attach style like spacing, color, font, etc. to HTML documents. Cascading style sheets work similarly to a template; permitting web developers to label style for an HTML element and after that apply it to the number of web pages required. Thus, Cascading Style Sheets (CSS) are collections of formatting rules, which control the appearance of content in a web page. With CSS styles you have great flexibility and control of the exact page appearance; from precise positioning of layout to specific fonts and styles.