Using Percentage Values in Responsive Web Design
When you are changing what your pages look like as they are seen from desktop to laptop to mobile phone to big screen TV, you can code your CSS in thousands of different fashions. You can use pixels or ems, but many designers us percentage values. This is kind of nice, I like it because the page flows on a big screen as the person makes their page wider or thinner on a desktop or laptop.
Using percentage values in a responsive web design page is a little tricky, because all of the time, as a designer plugging in your code, you have to think to yourself, “Self, what box am I working on right now, and what percentage value am I adding here.
This video introduces using percentage values in responsive web design.