Cascading Style Sheets

CSS or Cascading Style Sheets, is one of the three components that make up the basic building blocks of any web page. HTML is for creating the basic framework of a webpage, Javascript handles any coding features and interactive elements built into a page, while CSS handles the styling, like colors and font sizes.

HTML can do most of the same things as CSS, but CSS is preferred, especially in modern day, since HTML is not nearly as efficient, nor are it's standards as well maintained for those purposes.