NOTE: These notes are based on Section 5 in Build Responsive Real World Websites with HTML5 and CSS3 by Jonas Schmedtmann --- so they are his design opinions :)

Responsive Web Design

1. Fluid grid: all layout elements are sized in relative units, such as percentages, instead of absolute units like pixels
2. Flexible images: are also sized in relative units
3. Media queries: allow us to specify different CSS style rules for different browser widths