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.
PEF is a highly specialized raster image format. Created by the manufacturer of Pentax cameras for storing digital images taken by these devices. The name is an abbreviation for Pentax Electronic File. PEF files are digital photographs (RAW) without any compression, color editing or distortion. Data taken directly from the Pentax camera sensor. This format is also used by some Samsung cameras. At the same time, PEF format files are not compatible with image viewers, they cannot be printed and edited in graphic editors, they are not available for posting online. All this is possible only when converting to another format.