this is a new format that supports lossless and loss compression quality for images on the Internet. The Google Company developed this format specifically to do work online as quickly and conveniently as possible. The main advantage is that its file size is small compared to other image formats, but similar in image quality.
A bitmap image in the Portable Any Map format that was originally developed for processing and storing several types of monochrome and color images without compression as well as grayscale images. Bitmap graphics data in a PNM file are stored using ASCII or binary structure.