PNG is a raster image format developed by PNG Development Group. The name PNG is an abbreviation for Portable Network Graphic. This image format is used primarily on the Internet for posting on web pages, since PNG files use Deflate compression without losing quality. The development of this format was undertaken in order to replace the GIF format, to which there were many complaints. PNG's image quality and specifications were much better, but unlike GIF, it does not support animation and uses the CMYK palette.
TGA is a long-used raster graphic format. It was developed by Truevision Inc. (now Pinnacle Systems) back in 1984. It was initially used by the developer only for its own graphic adapters, but gradually gained popularity (primarily in the field of video processing and animation). Widely used in computer games, where it is used to store textures (including 3D video games). The name of the format comes from Targa Graphic. TGA files may partially contain image transparency information. They can become the main one for creating GIFs.