This document provides an introduction to Cascading Style Sheets (CSS) including its syntax, types, selectors and an example program. CSS allows styling web pages by separating design from content. CSS rules consist of selectors and declaration blocks with properties and values. There are three types of CSS styles: internal, inline, and external. Common selectors include element, ID, class, and grouping selectors. An example program demonstrates using CSS to style an HTML table with borders, padding, and rounded corners.