TXT is a file format that contains the text, organized in rows. Text files opposed binaries that contain data that is not intended for interpretation as a text (encoded sound or image). The text file can contain both formatted and unformatted text. Since the very simple text files, they are frequently used for storing data.
This is an image format that is used for visualization in the Khoros software suite. It is a kind of VIFF bitmap image. The format consists of color zones. It is used for visualization purposes in software for both commercial and scientific purposes.