This is a format created in the Acorn Draw program, intended for image visualization by using vector lines. It’s used for storing information in the publishing business (brochures, logotypes, etc.). The main advantage is it’s high quality source images when printing. It’s been in use since 1980.
This is an image file format written in textual form in the C language. It is used in the X Windows System interface for remote connections, which is designed to serve clients and servers. This format can be used to store color and monochrome images.