WebP is an open-source format for image files, raster images. Created in 2010 by Google for web graphics in order to quickly upload images to web pages. This is the main advantage of WebP files. Compression of images in this format can go with or without loss, depending on what level of quality you want to achieve. Thus, lossless compression is 26% better than in PNG files. If quality loss is acceptable, then compression in WebP format is 25-34% better than in JPEG files. Full support for WebP is not yet available on Firefox, Internet Explorer, and Safari.
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.