PNG, or Portable Network Graphics, is a file format designed for image compression. The file format was developed to replace Graphics Interchange Format, or GIF, which is another file format used to share compressed image files on the Internet.
PNG files allow for lossless compression, meaning no quality is lost to the image itself even after editing it. In comparison, the popular JPEG format is not lossless, but it often features a smaller overall file size. JPEG files can support up to 16.7 million colors, making them better suited for more advanced images and photographs.
PNG files were designed by an Internet committee with the purpose of being patent-free. Both GIF and PNG files allow users to freely create, view and send files in their respective formats, but developers looking to make software that can export into the GIF file format require permission from Unisys, the owner of the GIF format.
A feature called "opacity," included in the PNG format, allows users to make a certain color in an image transparent, and to define the overall degree of the transparency. In addition, PNG supports gamma correction, a feature that allows users to adjust the image's color brightness as required by specific display manufacturers.