PNG - technical definition

(Portable Network Graphics) A bitmapped graphics file format endorsed by the World Wide Web Consortium. It is expected to eventually replace the GIF format, because there are lingering legal problems with GIFs. CompuServe owns the format, and Unisys owns the compression method. In addition, GIF is a very basic graphics format that is limited to 256 colors (8-bit color).

PNG provides advanced graphics features such as 48-bit color, including an alpha channel, built-in gamma and color correction, tight compression and the ability to display at one resolution and print at another. See GIF.