The G3 format is used to compress image files in TIFF format when sending faxes. The compression algorithm allows for the use of a standard 10-times compression, which can be increased. It is used to remove excess image data, which makes it possible to reduce the size of the image and speed up delivery.
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.