This pin is a cheat sheet of the most recent html coding; html 5. While in the context of the class we may not need to be extremely familiar with all of the ins and out of computer programming and web design, the text explains html as an important part of web design. It explains that, "html allows you to put tags around your text so that the browser knows how to display it on the screen (182)."
Quick look into CSS3 properties: border-radius, opacity, border-image, background, linear-gradient, box-shadow, RGBA, transition, and text-shadow. Check http://caniuse.com/ to ensure you meet target browsers/devices and check http://html5please.com/#css to see how.