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.
PCX is standard presentation graphics developed by ZSoft Korporation. Used graphics program ZSoft PC Paintbrush for MS-DOS, word processing and desktop publishing applications, such as Microsoft Word and Ventura Publisher. Not as popular analog BMP, although supported by specific graphics editors such as Adobe Photoshop, Corel Draw, GIMP and others.