HTML stands for Hyper Text Markup Language, which is the most widely used language on Web to develop web pages. HTML created by Berners-Lee in late 1991. CSS invented by Håkon Wium Lie on October 10, 1994, and maintained by a group of people within the W3C called the CSS Working Group.
CSS introduced to provide more control to improve the presentation of web pages. It is used to control the style of a web document in a simple and easy way. Cascading Style Sheets, level 1 (CSS1) was came out of W3C as a recommendation in December 1996. This version describes the CSS language as well as a simple visual formatting model for all the HTML tags.
CSS is a simple design language intended to simplify the process of making web pages presentable.
CSS is easy to learn and understand but it provides powerful control over the presentation of an HTML document. Most commonly, CSS is combined with the markup languages HTML or XHTML.