| A | B |
|---|
| Absolute units | A specific size |
| Bitmap Pixel | The smallest unit of data in a raster image |
| Device Pixel | The tiniest physical unit in a display; also known as a physical pixel |
| Em space | 1 em equals the current font size; in a Web browser it equals 16 px |
| Fixedwidth Layout | The width of the site is bound to a certain number of pixels |
| Fluid Layout | The web design’s dimensions are defined in percentages rather than pixels. |
| Media Query | A CSS specification that allows designers to target styles based on a number of device properties |
| Pixel Density | The number of device pixels on a physical surface; often measured in pixels per inch. |
| Pixels per Inch PPI | A measure of screen density refers to the number of device pixels on a physical surface. |
| Reference Pixel | A W3C standard based on an optical reference unit that might be twice the size of a hardware pixel. This new pixel should look exactly the same in all viewing situations. |
| Relative units | Size is set in relation to surrounding elements |
| Resolution | A simple count of the number of pixels across the entire width and height of a device |
| Responsive Web Design | Refers to using existing techniques involving flexible grid layout, flexible images, and media and media queries into a unified approach to web design. |
| Scalable Vector Graphics SVG | Defines vector-based graphics that can be embedded directly into a Web page; SVG is a World Wide Web Consortium recommendation. |
| Vector graphics | Type of graphic that does NOT lose quality when zoomed or resized. |
| Viewport | The rectangular area (measured in pixels) that is viewable on a device screen. |
