It means that CtrlView analyses content of the file and determines its format. If file format is among supported file types, CtrlView will visualize this file in a correct form. If file type is unknown for CtrlView, it will be visualized in ASCII file form or in binary file form. Any file also can be opened manually as ASCII or binary so you have an ability to look inside the file at any time.
CtrlView was developed using of latest visual and programming technologies. This strongly Object Oriented Designed software uses OpenGL for 3D rendering, so-called "skins" for user friendly interfaces based on Zinc Application Framework, multidimensional trees in the internal data structure for the fast and accurate file parsing and rendering, Independent JPEG Group's software and many other interesting things.
CtrlView is an absolutely indispensable tool if you deal with a huge amount of plot files or 3D models files and want to look for something and print it or convert into another format.