Portable Network Graphics (PNG) is a bitmapped image format that employs lossless data compression. PNG was created to improve upon and replace the GIF format, as an image-file format not requiring a patent license. It is pronounced /ˈpɪŋ/ ping[1] or spelled out as P-N-G. The PNG initialism is optionally recursive, unofficially standing for “PNG's Not GIF”.
PNG supports palette-based (palettes of 24-bit RGB colors), greyscale or RGB images. PNG was designed for transferring images on the Internet, not professional graphics, and so does not support other color spaces (such as CMYK).
PNGs are ideal for saving icons, where information density is high and fidelity to the original image is paramount. For larger images JPGs are greatly preferred for size reasons.